[web] rename getMessageActionTooltipStyle to getTooltipStyle

Summary:
simple rename diff since the functionality of this function can be used for any tooltip not just the message action tooltip

Depends on D8819

Test Plan: flow and confirmed that there were no regressions with the web message tooltip

Reviewers: atul, kamil

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8826