Join circle proposal - enable visibility to the proposer

Related previous FE ticket: https://github.com/daostack/common-web/issues/1300
And BE ticket: https://github.com/daostack/common-backend/issues/1696#issuecomment-1533779284

If the BE support it
and if the proposer is not a member of the voters circle
we should:
Upon creation of join circle request, enable visibility also to the proposer
Add the proposer name to the visibility tag of this proposal

(maybe the BE endpoint for feed items (and inbox) should also be updated for this ?)