style(body-parser): don't shadow namespace

Shadowing causes issues with some parsers like `eslint-plugin-import`:
import-js/eslint-plugin-import#2861

Even if those plugins are at fault, this is an improvement in style:

Actually, the namespace is not necessary at all anymore after
DefinitelyTyped#57168

Hover doc looks slightly nicer:
`const bodyParser: BodyParser` instead of `const bodyParser: bodyparser.BodyParser`

`unnecessary-bind` linter message on `npm test body-parser` is from `master`.

types/body-parser/index.d.ts

@@ -16,92 +16,90 @@ import * as http from 'http';
 
 // for docs go to https://github.com/expressjs/body-parser/tree/1.19.0#body-parser
 
-declare namespace bodyParser {
-    interface BodyParser {
-        /**
-         * @deprecated  use individual json/urlencoded middlewares
-         */
-        (options?: OptionsJson & OptionsText & OptionsUrlencoded): NextHandleFunction;
-        /**
-         * Returns middleware that only parses json and only looks at requests
-         * where the Content-Type header matches the type option.
-         */
-        json(options?: OptionsJson): NextHandleFunction;
-        /**
-         * Returns middleware that parses all bodies as a Buffer and only looks at requests
-         * where the Content-Type header matches the type option.
-         */
-        raw(options?: Options): NextHandleFunction;
+interface BodyParser {
+    /**
+     * @deprecated  use individual json/urlencoded middlewares
+     */
+    (options?: OptionsJson & OptionsText & OptionsUrlencoded): NextHandleFunction;
+    /**
+     * Returns middleware that only parses json and only looks at requests
+     * where the Content-Type header matches the type option.
+     */
+    json(options?: OptionsJson): NextHandleFunction;
+    /**
+     * Returns middleware that parses all bodies as a Buffer and only looks at requests
+     * where the Content-Type header matches the type option.
+     */
+    raw(options?: Options): NextHandleFunction;
 
-        /**
-         * Returns middleware that parses all bodies as a string and only looks at requests
-         * where the Content-Type header matches the type option.
-         */
-        text(options?: OptionsText): NextHandleFunction;
-        /**
-         * Returns middleware that only parses urlencoded bodies and only looks at requests
-         * where the Content-Type header matches the type option
-         */
-        urlencoded(options?: OptionsUrlencoded): NextHandleFunction;
-    }
+    /**
+     * Returns middleware that parses all bodies as a string and only looks at requests
+     * where the Content-Type header matches the type option.
+     */
+    text(options?: OptionsText): NextHandleFunction;
+    /**
+     * Returns middleware that only parses urlencoded bodies and only looks at requests
+     * where the Content-Type header matches the type option
+     */
+    urlencoded(options?: OptionsUrlencoded): NextHandleFunction;
+}
 
-    interface Options {
-        /** When set to true, then deflated (compressed) bodies will be inflated; when false, deflated bodies are rejected. Defaults to true. */
-        inflate?: boolean | undefined;
-        /**
-         * Controls the maximum request body size. If this is a number,
-         * then the value specifies the number of bytes; if it is a string,
-         * the value is passed to the bytes library for parsing. Defaults to '100kb'.
-         */
-        limit?: number | string | undefined;
-        /**
-         * The type option is used to determine what media type the middleware will parse
-         */
-        type?: string | string[] | ((req: http.IncomingMessage) => any) | undefined;
-        /**
-         * The verify option, if supplied, is called as verify(req, res, buf, encoding),
-         * where buf is a Buffer of the raw request body and encoding is the encoding of the request.
-         */
-        verify?(req: http.IncomingMessage, res: http.ServerResponse, buf: Buffer, encoding: string): void;
-    }
+interface Options {
+    /** When set to true, then deflated (compressed) bodies will be inflated; when false, deflated bodies are rejected. Defaults to true. */
+    inflate?: boolean | undefined;
+    /**
+     * Controls the maximum request body size. If this is a number,
+     * then the value specifies the number of bytes; if it is a string,
+     * the value is passed to the bytes library for parsing. Defaults to '100kb'.
+     */
+    limit?: number | string | undefined;
+    /**
+     * The type option is used to determine what media type the middleware will parse
+     */
+    type?: string | string[] | ((req: http.IncomingMessage) => any) | undefined;
+    /**
+     * The verify option, if supplied, is called as verify(req, res, buf, encoding),
+     * where buf is a Buffer of the raw request body and encoding is the encoding of the request.
+     */
+    verify?(req: http.IncomingMessage, res: http.ServerResponse, buf: Buffer, encoding: string): void;
+}
 
-    interface OptionsJson extends Options {
-        /**
-         *
-         * The reviver option is passed directly to JSON.parse as the second argument.
-         */
-        reviver?(key: string, value: any): any;
-        /**
-         * When set to `true`, will only accept arrays and objects;
-         * when `false` will accept anything JSON.parse accepts. Defaults to `true`.
-         */
-        strict?: boolean | undefined;
-    }
+interface OptionsJson extends Options {
+    /**
+     *
+     * The reviver option is passed directly to JSON.parse as the second argument.
+     */
+    reviver?(key: string, value: any): any;
+    /**
+     * When set to `true`, will only accept arrays and objects;
+     * when `false` will accept anything JSON.parse accepts. Defaults to `true`.
+     */
+    strict?: boolean | undefined;
+}
 
-    interface OptionsText extends Options {
-        /**
-         * Specify the default character set for the text content if the charset
-         * is not specified in the Content-Type header of the request.
-         * Defaults to `utf-8`.
-         */
-        defaultCharset?: string | undefined;
-    }
+interface OptionsText extends Options {
+    /**
+     * Specify the default character set for the text content if the charset
+     * is not specified in the Content-Type header of the request.
+     * Defaults to `utf-8`.
+     */
+    defaultCharset?: string | undefined;
+}
 
-    interface OptionsUrlencoded extends Options {
-        /**
-         * The extended option allows to choose between parsing the URL-encoded data
-         * with the querystring library (when `false`) or the qs library (when `true`).
-         */
-        extended?: boolean | undefined;
-        /**
-         * The parameterLimit option controls the maximum number of parameters
-         * that are allowed in the URL-encoded data. If a request contains more parameters than this value,
-         * a 413 will be returned to the client. Defaults to 1000.
-         */
-        parameterLimit?: number | undefined;
-    }
+interface OptionsUrlencoded extends Options {
+    /**
+     * The extended option allows to choose between parsing the URL-encoded data
+     * with the querystring library (when `false`) or the qs library (when `true`).
+     */
+    extended?: boolean | undefined;
+    /**
+     * The parameterLimit option controls the maximum number of parameters
+     * that are allowed in the URL-encoded data. If a request contains more parameters than this value,
+     * a 413 will be returned to the client. Defaults to 1000.
+     */
+    parameterLimit?: number | undefined;
 }
 
-declare const bodyParser: bodyParser.BodyParser;
+declare const bodyParser: BodyParser;
 
 export = bodyParser;