Add e2e tests for generated server project

[ghost]

It is useful to have end-to-end test classes for every controller. Now there is a npm script test:e2e for an app test that fails. According nestjs standard, rename e2e test with .e2e-spec suffix and jest file with .e2e.config.

[ghost]

We need to fix the app main e2e test and provide a e2e test for every controller generated by entity and/or controller generator, in order to check CRUD operations.

• A valid link on how to e2e test: https://docs.nestjs.com/fundamentals/testing#end-to-end-testing
• Remember to mock security (overrideGuard())
• For the controller with repository, mock service: https://github.com/nestjs/nest/blob/master/sample/01-cats-app/e2e/cats/cats.e2e-spec.ts
• So add controller e2e test for entity-server and controller generators (fixing related unit tests of blueprint)

[ghost]

With https://github.com/jhipster/generator-jhipster-nodejs/commit/d9579e7152d609d783733d7185de5bc843c2131b I have added test profile for typeORM (sqlite in memory), renamed app e2e test and fix it. it misses to do a mocking way for security and service.

[ghost]

Added with #102