[lib] moved ModalOverlay component from web to lib

Summary:
moved modal-overlay.react and modal-overlay.css from web to lib.

Depends on D5364
Linear Task: ENG-2038

Test Plan:
Please watch the video to see that there are no visual or performance regressions with the migration of ModalOverlay from web to lib

Reviewers: atul, rohan, abosh, przemek

Reviewed By: atul, przemek

Subscribers: ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D5370