All externallib_test, generator_test and filter_test classes:
- Namespaced with component[\level2-API]
- Moved to level2-API subdirectory when required.
- Fixed incorrect use statements with leading backslash.
- Changed code to point to global scope when needed.
- Fix some relative paths and comments here and there.
- All them passing individually.
- Complete runs passing too.
Special mention to tests under testing/tests:
1) The core_testing component doesn't exist.
2) But testing/tests are allowed because there is a suite pointing to it (phpunit.xml).
3) So, the only possible namespace for them is "core".
4) And to avoid problems with other core testcases (under lib/tests)
they have been renamed to have testing_xxxx as prefix.
Finally, also modified calendar/tests/events/events_test.php because it uses
some renamed (core_calendar_externallib_testcase => \core_calendar\externallib_test)
classes.
All the setup/teardown/pre/post/conditions template methods
now are required to return void. This was warned with phpunit 7
and now is enforced.
At the same time, fix a few wrong function names,
provider data and param types, return statements...
1. getMock()
2. setExpectedException()
3. checkForUnintentionallyCoveredCode renamed to beStrictAboutCoversAnnotation
4. beStrictAboutTestSize renamed to enforceTimeLimit
5. UnitTestCase class is now fully removed.