MWEB-667

**DO NOT MERGE -- MOBILE WEB TEAM WILL CR AND QA IT FIRST**

* bunch of unit tests for existing PHP entry points,
* moved some existing logic from one place to another,
* added new `WikiaInteractiveMapsPermissionException`,
* implemented logic which disallows blocked user to create/delete/change maps.
Is there a point in doing that? You say that it can be called `any` number of times (including 0) and you don't mock `getData` method.

IMO it does nothing ;)