[web] factor out app container position info logic out of tooltip utils

Summary:
factor out app container position info logic into a function in a seperate window utils file.

Linear Task: ENG-2849

Test Plan: flow and no regressisions in the tooltip positioning

Reviewers: atul, tomek, rohan

Reviewed By: tomek

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D6786