Create sidebar from tooltip

Summary: This diff will be updated, some things are still missing: creating sidebars from messages different than text message, checking create_sidebar permission.

Test Plan:
Test if new button is visible in tooltip for text messages. Test if pressing navigates to pending thread with visible message according to pressed message. Test if sending message creates new sidebar.
Test if pressing on message that was already used to create sidebar navigates to existing ine. Test if sidebar source message and create sidebar message are visible.

Reviewers: ashoat

Reviewed By: ashoat

Subscribers: palys-swm

Differential Revision: https://phabricator.ashoat.com/D579