test: Clean up data providers that should be static

Follows-up b36d883.

By far most data providers are static (and PHPUnit expects them
to be static and calls them that way).

Most of these classes already had their data providers static
but additional commits sloppily introduced non-static ones.

* ResourceLoaderWikiModuleTest, 8968d8787f.
* TitleTest, 545f1d3a73.
  Odd unused method 'dataTestIsValidMoveOperation' was introduced
  in 550b878e63.
* GlobalVarConfigTest, a3e18c3670.

Change-Id: I5da99f7cd3da68c550ae507ffe1f725d31e7666f