[web] Refresh invite links

Summary:
Every time a window becomes active, fetch invite links so that we can display the most recent version without requesting too often. Ultimately, we would like to have a mechanism where every invite link change results in updates being sent to interested clients.

Depends on D8239

Test Plan:
Check if actions are dispatched when the window becomes active.
Modify website responder so that an empty invite links store is returned. Check if the links are updated after successful result is returned from the server when a window becomes active.

Reviewers: bartek, kamil, inka

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D8246