resourceloader: Improve coverage in ResourceLoaderTest.php
* Fix signature of makeLoaderSourcesScript() to match
the change in behaviour since
e103ba265.
* Consistently order providers before the test.
* Simplify testRegisterValid() and remove needless @depends.
* Remove unused private method stripNoflip().
Coverage:
* Expand test coverage for register().
* Add tests for getModuleNames().
* Add tests for getModule().
* Expand test coverage for addSource().
(case of invalid array)
* Expand test coverage for makeLoaderImplementScript().
(case of unwrapped user script, and case of invalid scripts)
* Add tests for makeLoaderSourcesScript().
Change-Id: Ibca3e486fcd3664f171f135327a0f340ee6da9ee