[web] Make pressing Inbox button reset selected community

Summary:
issue: https://linear.app/comm/issue/ENG-3176/make-pressing-a-drawer-item-in-chat-tab-filter-available-chats
We want pressing the "Inbox" button to reset the picked community

Test Plan: Set some community in state.pickedCommunityIDs.chat and checked that pressing "Inbox" resets it

Reviewers: kamil, tomek, michal

Reviewed By: kamil

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D6972