Reland invisibles (#19846)

Release Notes:

- Show invisibles in the editor

Relands #19298 

Trying to quantify a performance impact, it doesn't seem to impact much
visible in Instruments or in a micro-benchmark of Editor#layout_lines.
We're still taking a few hundred micro-seconds (+/- a lot) every time.
The ascii file has just ascii, where as the cc file has one control
character per line.

<img width="1055" alt="Screenshot 2024-10-28 at 12 14 53"
src="https://github.com/user-attachments/assets/1c382063-bb19-4e92-bbba-ed5e7c02309f">
<img width="1020" alt="Screenshot 2024-10-28 at 12 15 07"
src="https://github.com/user-attachments/assets/1789f65e-5f83-4c32-be47-7748c62c3703">