Use proper error code and message

[roeierez]

Propagating the error code and message to the errors thrown from the native layer.
To make it generic reflection is used in both platform to extract the class name, e.g:
SdkError.Generic => Generic

[dangeross]

I think it's better with the code set to the enum value, but there is an inconsistency in the message between iOS and android. The iOS error message for example is still wrapped with InitFailed(message: \"...\") where on android it is not.

iOS:

{
  "code": "InitFailed",
  "message": "InitFailed(message: \"Failed to initialize the SDK: Failed to connect to Greenlight: Failed to decrypt credentials, seed doesn\\'t match existing node\")",
  "domain": "BreezSDK.SdkError",
  "userInfo": {},
  "nativeStackIOS": [ ... ]
}

android:

{
  "nativeStackAndroid": [ ... ],
  "userInfo": null,
  "message": "Failed to initialize the SDK: Failed to connect to Greenlight: status: Internal, message: \"Unable to register node: not authorized: an invite code or a partner certificate is require to register a new node (see https://bit.ly/glinvites for details\", details: [], metadata: MetadataMap { headers: {\"content-type\": \"application/grpc\", \"date\": \"Sun, 23 Jul 2023 18:26:40 GMT\", \"content-length\": \"0\"} }",
  "code": "InitFailed",
  "line": 2527,
  "column": 45,
  "sourceURL": "http://10.0.2.2:8081/index.bundle?platform=android&dev=true&minify=false&app=com.example.breezsdk&modulesOnly=false&runModule=true"
}

the best way I could come up with to solve this is changing the rejectErr func to also reflect the enum's associated variables:

    func rejectErr(err: Error, reject: @escaping RCTPromiseRejectBlock) {
        var errorCode = "Generic"
        var message = "\(err)"
        if let sdkErr = err as? SdkError {
            if let sdkErrAssociated = Mirror(reflecting: sdkErr).children.first {
                if let associatedMessage = Mirror(reflecting: sdkErrAssociated.value).children.first {
                    message = associatedMessage.value as! String
                }
            }
        }
        reject(errorCode, message, err)
    }

which results in:

{
  "code": "Generic",
  "message": "Failed to initialize the SDK: Failed to connect to Greenlight: status: Internal, message: \"Unable to register node: not authorized: an invite code or a partner certificate is require to register a new node (see https://bit.ly/glinvites for details\", details: [], metadata: MetadataMap { headers: {\"content-type\": \"application/grpc\", \"date\": \"Sun, 23 Jul 2023 20:07:25 GMT\", \"content-length\": \"0\"} }",
  "domain": "BreezSDK.SdkError",
  "userInfo": {},
  "nativeStackIOS": [ ... ]
}