[lib] Introduce useFilteredChatListData hook

Summary: Introduced more generic version of useFlattenedChatListData hook to use it with custom filter function in subchannels modal.

Test Plan: In web app, current logic for displaying chat list data in thread list should remain unchanged. The new function will be used in future diff.

Reviewers: palys-swm, ashoat

Reviewed By: ashoat

Subscribers: ashoat, Adrian, atul, karol-bisztyga, benschac, yayabosh

Differential Revision: https://phabricator.ashoat.com/D3598