Improve focus management for a better keyboard navigation

[dgdavid]

There is an annoying problem in the current UI when using the keyboard instead of mouse: users have to tab too much for reaching the element they might be interested on. Moreover, when navigation from one route to another the focus goes to the very beginning instead of get trapped by the loaded content which would fit average users expectations.

As an example, use the keyboard for going from the Overview page to the user creation form and reach the Fullname input. Have a lot of fun hitting the Tab 😜

Related, old, and still open (at the time of writing) discussion in react-router, remix-run/react-router#9555

[dgdavid]

When time permits, I will try to add more information here. The idea is to find a robust solution that allow us to move forward a11y of Agama.

[dgdavid]

On November 11th we have got a focus-related suggestion through bugzilla, see https://bugzilla.suse.com/show_bug.cgi?id=1233161