#416 Add tests for CIF common checks

Notes:

• The CIF common checks are not application framework applications, but more like library functionality. I therefore added an application specifically for testing. Then I just used the integration test framework as usual.
• I named the tests after the check class that they use, to allow the test application to be reused for all them.
• The expression and type checks are parameterized. Hence, I created in the test plugin some derived classes. They essentially test per level (based on the number of '_' characters in the enum values). This allows testing for instance PLUS vs PLUS_INT vs PLUS_INT_RANGED. It doesn't test all 'logic paths', as PLUS_INT_RANGED and PLUS_INT_RANGELESS are still tested together. But we get quite some coverage this way.

I recommend reviewing the total changes, rather than the individual commits.

Closes #416 (closed)