Allow changing/editing PMP on messages

[j0lol]

Description

Adds an option on messages to change the PMP

Part of #1279

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).

[j0lol]

PersonaPicker.tsx is quite messy from all of this, will try to refactor. Reviews welcome on how to make this all cleaner.

[j0lol]

Currently noticed one bug: picking a room persona doesn't visually update correctly (button still works as normal.) But this was not introduced in this PR (I checked dev and saw the same bug, soo...)

Any reviews on that would be nice but not needed