[FEATURE] Make domain model extendable

By adding a specialized auto loader that uses a cache manager to create
compiled cache files, its now possible to extends models with custom
fields and corresponding getter and setter.

Resolves: #52606
Releases: 4.5

Change-Id: I4a7354fb5848bfa4f080cd7412523673962dec81
Reviewed-on: https://review.typo3.org/24497
Reviewed-by: Simon Schmidt
Tested-by: Simon Schmidt
Reviewed-by: Sebastian Fischer
Tested-by: Sebastian Fischer