Update vim and helix replace to repeat based on grapheme count instead of
byte length or Unicode scalar count.

This fixes cases where a single visible character is made up of multiple
bytes or scalars, such as decomposed characters like `e\u{301}` and emoji.

Closes #51772 

Release Notes:

- Fixed vim/helix's replace action to take into consideration grapheme
count

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Co-authored-by: dino <dinojoaocosta@gmail.com>