Explore replacing cdk focus trap with native HTML inert

[jelbourn]

The new HTML inert attribute is a native solution to the very manual focus trapping we employ today. We should explore whether we can drop the entire focus trap subpackage in favor of people directly using inert. It will be some time until browsers fully support this, but it's on track for all of Chromium/Firefox/Safari.

See
https://developer.chrome.com/blog/inert/
https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/inert
https://caniuse.com/mdn-api_htmlelement_inert

[JelleBruisten]

I looks like inert is currently stable, I was investigating a issue where a element outside of the dialog kept focus when opening a angular material dialog. ( pressing the enter on keyboard would interact with previous element ).

Are there any plans to pick this up? inert seems to be stable in all browsers