Feat: add quickreply keybindings

[CodeF53]

Description

This adds the keybinds ctrl+up/ctrl+down to be used to cycle what message you are replying to. This is inspired by the vencord plugin QuickReply

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

I couldn't get pnpm dev to run so I used an llm to help me figure that out so I could test my changes, but no code in this pr has been touched by an llm

[CodeF53]

quickreplydemo.mp4

I feel like sable missing the highlight for the message you are replying to makes it harder to use this than it is on discord, but adding a highlight for the reply target is out of scope for this pr in my opinion

[dozro]

hey it seems like you're missing a changeset. Can you please add a changeset, as described here https://github.com/SableClient/Sable/blob/dev/CONTRIBUTING.md#documenting-a-change

Thank you :3

[CodeF53]

Sorry about all the force pushes, nixos is really strict about one commit per file changed in a pr and it has formed some habits in me

[dozro]

code lgtm