Add Sorting Option for Budget Proposals by Latest Comment

[bosko-m]

Description

Introduce a new sorting option to sort budget proposals by the latest comment.
This will allow users to easily find the most recently discussed proposals and follow ongoing conversations.

Acceptance Criteria

• A "Latest Comment" option is added to the sorting dropdown for budget proposals.
• Selecting this option sorts proposals based on the timestamp of the most recent comment.
• Sorting applies across all views where budget proposals are listed.

[danbaruka]

I’d be happy to work on this feature. Let me know if it’s available and if there are any design considerations to keep in mind before I begin.