[TASK] Add FileCollectionRegistry

The classes belonging to the FileCollection types are hardwired
in ResourceFactory::createCollectionObject(), therefore you can
not use your own types.

This change introduces a Registry API that makes it possible to
register your own FileCollection type + class and has a generic
way to add the new type to TCA[sys_file_collection].

How to use:
- Register type in ext_localconf.php
  $register->registerFileCollectionClass(full_class_name, your_type);
- Add type to TCA in Configuration/TCA/sys_file_collection.php
  $register->addTypeToTCA(your_type, label, needed_fields);
  return $GLOBALS['TCA']['sys_file_collection'];

Resolves: #53910
Documentation: #56032
Releases: 6.2
Change-Id: Id6cb1c7a59f741b28fee7bdfef32890f34a072a5
Reviewed-on: https://review.typo3.org/27257
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters