[web] move getTooltipPositionStyle into tooltip-utils

Summary:
simple move diff. Thought it made more sense for getTooltipPositionStyle to be living in tooltip-utils instaed of tooltip-action-utils

Depends on D8827

Test Plan: flow and confirmed that the message tooltip looks and behaves as expected

Reviewers: atul, kamil

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8828