fix(common): set name of httpexception as class name

Added a method to set name property of exception object equal to class name which currently is always Error. Updated tests.

Closes nestjs#5809

Author: DrPuneetGaur

integration/graphql-code-first/e2e/pipes.spec.ts

@@ -33,6 +33,7 @@ describe('GraphQL Pipes', () => {
               code: 'INTERNAL_SERVER_ERROR',
               exception: {
                 message: 'Bad Request Exception',
+                name: 'BadRequestException',
                 response: {
                   message: [
                     'description must be longer than or equal to 30 characters',

packages/common/exceptions/http.exception.ts

@@ -40,7 +40,7 @@ export class HttpException extends Error {
   ) {
     super();
     this.initMessage();
-    this.setName();
+    this.initName();
   }
 
   public initMessage() {
@@ -79,7 +79,7 @@ export class HttpException extends Error {
       : { statusCode, message: objectOrError, error: description };
   }
 
-  public setName(): void {
+  public initName(): void {
     this.name = this.constructor.name;
   }
 }