Add strip_bbcode() method to String

[ztc0611]

Adds a function to strip bbcode tags out of strings.

Example Code:

var s = "[color=#ffffff]Hello![/color]
print(s.strip_bbcode())

Result: Hello

Closes godotengine/godot-proposals#5056

[ztc0611]

Sorry for that, I made the mistake of putting new changes on the same branch as this PR. Corrected now.

[ztc0611]

Any update on this? Since I was silly and didn't correctly branch from master, it means I can't submit my other PR about re-adding the center window function until this one is gone.

[Chaosus]

Any update on this? Since I was silly and didn't correctly branch from master, it means I can't submit my other PR about re-adding the center window function until this one is gone.

Accepting the pull request is usually a long process - some hours, days or weeks, and sometimes it even takes years, in general if you have such problem - there is no shame to close the PR and then re-open a fixed version.