Update OverlayPlugin to new CEF version

[quisquous]

Mostly I just wanted check if this was still on the radar / if there were blockers / what the schedule looked like for this chnage.

This is coming up somewhat because I would like to change cactbot triggers over to TypeScript. Doing that (reasonably?) involves adding some optional chaining and nullish coalescing that isn't available in the OverlayPlugin version of CEF. Using those will cause the javascript transpiled version of triggers (for users to look at as a reference for user triggers) to become extremely unreadable.

[chalkpe]

It seems CEF version is stuck on 75 since two years ago?

+1 for Intl.NumberFormat notation option, useful for 23.1k-like DPS abbreviation formatting, is available since Chrome version 77 and many new modern web techs