[RTL] Add `pop_all`, `push_context` and `pop_context` methods, and use it for `print_rich` to avoid unclosed tags.

[bruvzg]

Fixes https://github.com/godotengine/godot/issues/78520

Before	After

[MewPurPur]

Are there any benefits to doing this other than less code? Just curious if I should still do things the old way unless necessary.

[bruvzg]

Are there any benefits to doing this other than less code?

pop_all should be faster, but in real use cases it probably won't have any visible effect. The only real advantage, there's no need to count push_ calls to match with the same number of pops.

[YuriSizov]

The only real advantage, there's no need to count push_ calls to match with the same number of pops.

I believe in our built-in documentation we have plenty of cases where we need to pop N levels from the stack, but not all of it. Would something like a scope or a context make sense as well?

push_context(); // Start counting pushes.
push_...();
push_...();
push_...();
push_...();
pop_context(); // Pops 4 stack levels and removes context.

[bruvzg]

Added push_context / pop_context as well.

[YuriSizov]

Thanks! Now someone could do a pass simplifying calls in the built-in help :)

[MewPurPur]

Code simplification with new methods? I'm in.