[lib] [refactor] [ENG-530] add memo in inline sidebar hook

Summary: updating the hook per my comment in my last diff: https://phabricator.ashoat.com/D3879#inline-23803

Test Plan: use the application like normal. replied should reflect in a sidebar as they do normally.

Reviewers: atul, def-au1t, yayabosh, ashoat

Reviewed By: ashoat

Subscribers: palys-swm, Adrian, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3887