Fixes #6103: Improved codeception config in app templates to ease testing of advanced app on multiple hosts

Fixes #4827: default config for functional tests of both basic and advanced app now turns off CSRF validation while providing commented out alternative setting cookie domain to localhost

speed up process a lot because 3 composer updates are reduced to one

Used a single database and a single CLI entry point for all test types. Added faker to basic app dev requirements.

Exposed basic app entry URL via codeception.yml, refactored configs of advanced app to read from config and define entry script in a single place

- Moved everything test-related into `tests` directory. Codeception tests are in `codeception`.
- Removed database module since we're using fixtures and migrations.
- Moved console entry points and bootstrap into `tests/codeception/bin`.
- Adjusted travis build scripts.
- Adjusted documentation to be consistent and reflect changes made.