Create new error message.

Set404 is a function that returns a new error message with the standard code for "not found" (404).

SetDefaultErrBodyRequest generates an error response for a request with a default body.

SetNewBadRequest set error as bad request code 400 and custom message.

SetNewBadRequest returns a new error message with the standard code for a bad request (400).

SetNewError is function return new error message.

SetNewInternalError is function return new error message with internal server error standard code(500).

SetNewUnauthorizedError is function return new error message with unauthorized error code(401).

DefaultInputBody return bad request for bad body request.