New room list: Tile context menu for tagging

[turt2live]

Outstanding concerns:

• Considering New room list: Archived view #14038, what are the options themselves?
  • Currently we have Favourite and Low Priority, but if Low Priority goes away then the favourite interaction might feel bare.
• Designs needed for toggled-on state (bold?).

Development:

• Make it work
• Designs as appropriate

[t3chguy]

Designs needed for toggled-on state (bold?).

Presumably this should match the Notifications menu which gets accented and a checkmark:

[t3chguy]

matrix-org/matrix-react-sdk#4858 gets rid of the Low Priority option as per the design

[turt2live]

Actually going to merge this in with #14038 for ease of representation