All restore_date_test, api_test, rule_test, plugin_test,
manager_test, helper_test testcase classes:
- Namespaced with component[\level2-API]
- Moved to level2-API subdirectory when required.
- Fixed incorrect use statements with leading backslash.
- Remove file phpdoc block
- Remove MOODLE_INTERNAL if not needed.
- 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:
- All restore_date_test cases have been put under xxx\backup
level 2 (valid API) namespace.
