Split functionalJS test into a few smaller chunks

Problem/Motivation

It's getting too big and we have a method for creating test content programmatically so it can be done before each test except the content creation one obviously.

Proposed resolution

Proposed new test structure:
1. Content creation test (admin & teacher), course 1, course 2, exam
2. Nav block test
3. LMS Reference Table test
4. LMS Entity constraints test
5. Data integrity checks test
6. Revision reference mode test
7. Random activities test
8. Hooks test

@todo Decide if all the above actually need to be functionalJS.