Optimize abstract platform

This PR optimizes the <code>AbstractPlatform</code> class in the following ways:

* Add dedicated use statemtent for each class import
* Add missing class imports
* Add missing phpDoc blocks for methods
* Fix existing phpDocs (parameters, return types, @throws tags, FQDN types, indentation etc.)
* "Normalize" phpDocs (consistent verbs for what a method does, reuse of certain phrases for similar method types etc.)
* Fix CS
* Improve certain code portions

I hope this is a welcomed improvement. It reads much better now and feels somewhat cleaner to me.