pat-inject modernization

[thet]

A side outcome of the pat-inject autoload-visible fixes.

Eventually this will be revisited later to rework pat-inject for a more readable, simpler and clearer structure.

The branch name is misleading.

[thet]

This is replaced by: #1222
Except for the Base prototype rework, which is obsolete on it's own since I'd use the class based pattern approach now.
However, reworking into a class-based pattern is intended as it will give us encapsulation. Now we cannot bind any variables on this but need to bind everything on the node element itself. This will make the code simpler, more readable and more error-prone.