Vraious fixes to DataTypesModulesTest

* Excluded it from regular phpunit runs, as it is not really part of the package (it needs MW)
* Fixed usage of wrong string concat operators
* Simplified test setup code and removed some invalid usage of phpunit
* Fixed @covers tag
* Moved class into namespace, leaving a deperacted inheritor
* Moved test class into modules to mirror production code

Change-Id: Iff63c2b2677285b5e59a143e12bc809e486e9d44