[Story] Mark a room or dm as favourite

[VolkerJunginger]

Description

As a user that has favourite room I want to mark these as favourites so that I can find the fast.

Figma

Acceptance criteria

• A room can be (un-) marked as favourite form the room-list and the room-details-page.
• There must be a visual (star-icon) in the room-headder (@amshakal ?) to show the user that this room is a favourite

Leads

• Tech: @ganfra
• Design: @amshakal

Size estimate

S/M/L

Dependencies

• None

Out of scope

• Nothing

Open questions

### Questions

Subtasks

### Android
- [ ] https://github.com/element-hq/element-x-android/issues/2208

### iOS
- [ ] https://github.com/element-hq/element-x-ios/issues/2320

### Rust
- [ ] https://github.com/matrix-org/matrix-rust-sdk/issues/3005

### Other

Sign-off

Android

• [ ] Design sign-off on completion
• [ ] QA sign-off on completion
• [ ] Product sign-off on completion

iOS

• [ ] Design sign-off on completion
• [ ] QA sign-off on completion
• [ ] Product sign-off on completion

[jplatte]

Favorite rooms are stored under m.favourite room account data. This should be pretty easy to integrate into RoomInfo on the Rust side, and expose to EX.

[manuroe]

@amshakal we would need some guidance on the design. Legacy apps do not have the same behavior.

[amshakal]

Not sure about adding a star to the room header but lets start with adding a button in the room details page. I added designs for it. I am slightly skeptical of changing the copy from favourite to un-favourite like we do for mute, unmute as the word is too long so would like to check if thats okay with everyone. Mark room as favourite:

Mark DM as favourite: