[web][fixed] Added FocusTrap for modals

Summary:
Diff which was reverted: https://phab.comm.dev/D7837
More info on why it was reverted: https://linear.app/comm/issue/ENG-3928/focustrap-causes-regressions-to-modals-in-landing

Added fallbackFocus option, which sets focus to div when there are no focusable elements inside the FocusTrap.

Old description:
We want to prevent users from focusing outside the modals. Added focus-trap-react library, to do that, and covered the modals that we use.

Test Plan:
Checked if in edit mode and in other modals user can't focus outside the modal using the tab.
Checked if the modals without focusable elements (i.g. in the investor's tab on the landing page) also work.

Videos: https://linear.app/comm/issue/ENG-3928#comment-13a62270

Reviewers: michal, inka, ashoat, ginsu

Reviewed By: ashoat

Subscribers: atul, tomek, ashoat

Differential Revision: https://phab.comm.dev/D7960