Uses the Overlay component for ClayModal

[matuzalemsteles]

As part of PR #5208, adds a new Overlay component that better handles a focus trap system and click outside the element, this has greatly reduced the duplicate code we have to solve the same problems in other Clay components.

The goal here is to remove the focus lock implementation that exists inside ClayModal and also the suppression of elements outside the modal in favor of using only Overlay. This will make maintenance a lot easier and ensure consistency of behavior and also accessibility improvements for all overlay related components.

[matuzalemsteles]

LPS Ticket: https://liferay.atlassian.net/browse/LPS-190526