add promote option to the dropdown menu, with API hook. Still need to add logic of showing
- The promote option on sidebar conversationbutton shows in another diff. Additonally,every dropdown. I need to add a loading statelogic in another diff to only show it in another diff toosidebars that can be promoted.
- Loading state needs to be added in another diff too.
https://linear.app/comm/issue/ENG-991/promote-sidebar-to-subthread-on-web