[suppressions] Allow suppressing individual rules within a tool

[mikeharder]

Add property "rules", which is a list of strings that are regexes matched against rule names.

export interface Suppression {
  tool: string;
  rules?: string[];
  paths: string[];
  reason: string;
}

Example:

- tool: TypeSpecValidation
  path: specification/monitor/**/tspconfig.yaml
  rules:
    - tspconfig-*-contains-package-name
    - tspconfig-js-*