Fix "run tests" button not launching the correct tests.

The initialize method was incomplete.
Add a section about how to use the SDK namespace in tests.
Move tests utilities from API to tests_utils.
Merge remote-tracking branch 'origin/topic/bf_organize_files' into develop

* origin/topic/bf_organize_files:
  Move tests utilities from API to tests_utils.
Merge remote-tracking branch 'origin/topic/bf_fix_test_docs' into develop

* origin/topic/bf_fix_test_docs:
  Add a section about how to use the SDK namespace in tests.
Merge remote-tracking branch 'origin/topic/fix_unit_tests_page' into develop

* origin/topic/fix_unit_tests_page:
  Fix "run tests" button not launching the correct tests.