Add support for saving or editing hotkey defaults in new updates

[Mm2PL]

Checklist

• [X] I'm reporting a problem with Chatterino
• [X] I've verified that I'm running the most recent nightly build or stable release
• [X] I've looked for my problem on the wiki
• [X] I've searched the issues and pull requests for similar looking reports

Describe your issue

If we wanted to edit default hotkeys in the code, it's not really possible. This is probably my issue xd

Screenshots

No response

OS and Chatterino Version

latest master