feat(a11y): Globally improve accessibility for screen reader users

When the toolbox is hidden and due to a ReactFocusLock instance the
focus is returned to the toolbox the whole page scrolls to the toolbox
which is positioned outside of the viewport in the bottom.
Then when the animation for displaying the toolbox is started the
scenario looks like the large video is jumping.
Now we don't return the focus from ReactFocusLock to elements which are
not part of the viewport.

Fix some errors. Remove @ts-ignores
Convert some files to TS
Remove some eslint-disables

Co-authored-by: Calinteodor <calin.chitu@8x8.com>
Co-authored-by: Robert Pintilii <robert.pin9@gmail.com>

- apply theming to various buttons