[web] Add to calendar filters reducer logic for handling the COMMUNITY filters
In D6457 I added architectural changes that allow for a new type of calendar filter. In this diff I add logic to the web reducer, that will handle setting this state.
This used to be diff D6458, but I messed up somethin in my local git, and can't get that commit back, sorry.
Test Plan: Dispatch updateCalendarCommunityFilter and clearCalendarCommunityFilter actions, check in redux tools that they succeed, and redux state changes as expected.
Reviewers: kamil, tomek
Reviewed By: kamil, tomek
Subscribers: ashoat, atul
Differential Revision: https://phab.comm.dev/D6645