resourceloader: Improve coverage in ResourceLoaderTest.php

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