Escape characters on paste

[sharwell]

It would be nice to automatically escape special characters when pasting content into a string. If the paste operation triggered an escaping operation, then the first Undo operation after paste would undo just the character escaping.

First position of copied region	Pasting outside a literal	Pasting inside a literal
Inside a text literal	Unescape on paste	Correct escape sequences that change meaning
Outside a text literal	As-is	Escape on paste
Raw text (e.g. browser)	As-is	Escape on paste

[jinujoseph]

This should probably be a platform feature to benefit other langs , cc @olegtk

[sharwell]

Note that the escaping procedures for raw strings are more complicated, but the overall strategy holds. See #59820.

[CyrusNajmabadi]

Fixed fully with #61177.