[web] Added edit button to the Tooltip

Summary: Added Edit button to the tooltip, which selects a message for editing. It is shown only for messages in which the author is the viewer.

Test Plan:
Checked if the edit button displays correctly in the tooltip.
Checked if the state is correctly changed in dev tools.

Reviewers: michal, inka

Reviewed By: michal

Subscribers: ginsu, ted, ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7793