[lib][native][web] Show a message when a user is already a part of a community
Summary:
Introduce a new status to the modals meaning that a user already joined a community.
https://linear.app/comm/issue/ENG-4391/display-a-message-if-youre-already-part-of-a-community
Depends on D11812
Test Plan:
Checked on native and web:
- If accepting a link still works
- If a message is displayed when a user is already a part of a community
Reviewers: inka, ashoat
Reviewed By: ashoat
Differential Revision: https://phab.comm.dev/D11823