[keyserver] update fetchCommunityInfos to query by community ids

Summary:
In D11975, there was some feedback to have createOrUpdateFarcasterChannelTag query by a specific community to improve performance. This diff addresses that

Linear task: https://linear.app/comm/issue/ENG-8374/update-createorupdatefarcasterchanneltag-to-query-by-a-specific

Depends on D12062

Test Plan: Logged out return value of fetchCommunityInfos and confirmed that only one community was being returned

Reviewers: tomek, kamil

Reviewed By: tomek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12410