Cherry-picks for the godot-cpp 4.5 branch - 1st batch

[dsnopek]

The 1st batch of PR's marked with cherrypick:4.5

[Ivorforce]

Looks good to me.
The only cherry-pick I don't understand is #1868. Isn't that only required for 4.6+ bindings? (assuming that RequiredPtr will get merged in this cycle)

[dsnopek]

@Ivorforce Thanks!

The only cherry-pick I don't understand is #1868. Isn't that only required for 4.6+ bindings? (assuming that RequiredPtr will get merged in this cycle)

This one is included for a couple reasons:

• I always cherry-pick as many build system and binding_generator.py changes as possible, because the closer those are to master, the easier they are to maintain, and usually, changes in those places don't cause any issues. (I'm about to cherry-pick it to the 4.4 branch as well)
• The tests on Godot's CI run on godot-cpp version N-1, so we actually need this cherry-pick in order for tests to pass on Add RequiredParam<T> and RequiredValue<T> to mark Object * arguments and return values as required godot#86079