[lib] introduce barebones community types

Summary:
This diff introduces the barebones community types that will be used to build the community store. To keep things as simple as possible, I am just includinng the enabledApps since this will be needed for the web app redesign; however, I can imagine us wanting to extend this in the future when we build more community based features out

Linear task: https://linear.app/comm/issue/ENG-6157/introduce-community-types

Test Plan: flow

Reviewers: atul, kamil, inka

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11036