[native] introduce useReactionSelectionPopoverPosition hook

Summary:
introduce useReactionSelectionPopoverPosition hook. This hook will be used to help position the reaction selection popover based off the size/position of the message and chat window

Depends on D6447
Linear Task: ENG-2779

Test Plan: flow and this will be further tested in a subsequent diff

Reviewers: atul, tomek

Reviewed By: tomek

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D6453