4.x: align tests/testing module in MP

[tomas-langer]

We use tests module to host our own tests, and testing to host modules that are released and can be used by customers to test our code.
This approach is not done in microprofile, where we use tests for both purposes.
We should refactor this as follows:

microrprofile/tests - should contain tests for Helidon MP, modules can have sub-directories. tck directory stays here, as well as arquillian
microprofile/testing - our junit and testng support should be moved (or copied here) to new packages and modules (and the old one marked deprecated - we may want to do this in 3.x, deprecate the tests modules, and release 4 with testing only.

All MP tests from tests/integration should be moved to appropriate modules in microprofile/tests - such as to microprofile/tests/server, or microprofile/tests/tracing