[web] introduce community list

Summary:
This diff introduces the community list component that will be used in the navigation sidebar component (which will be introduced in a future diff)

For context on what this should look like here is a screenshot from the figma:

Part of https://linear.app/comm/issue/ENG-5947/list-of-all-top-level-communites-communities

Depends on D10359

Test Plan:
Please see the demo videos below

User with many communities:

user with not many communities:

Reviewers: atul, rohan, kamil

Reviewed By: rohan

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10360