[web] Rename sidebarTooltip to messageActionTooltip

Summary: Part of refactoring done with tooltipMenu introduction: sidebarTooltip can be used not only for sidebars action

Test Plan: Flow, check if tooltip looks and works as before

Reviewers: palys-swm, ashoat

Reviewed By: palys-swm, ashoat

Subscribers: ashoat, palys-swm, Adrian, atul

Differential Revision: https://phabricator.ashoat.com/D993