[web] introduce navigation sidebar

Summary:
After introducing all the parts for the navigation sidebar, this diff introduces the navigation sidebar component that brings all the buttons + community list together in one component

linear task: https://linear.app/comm/issue/ENG-5930/community-sidebar

Depends on D10363

Test Plan:
Please see screenshot below

Reviewers: atul, rohan, kamil

Reviewed By: rohan

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10364