Improve ARIA functionality in AI Lab extension

[odockal]

Is your enhancement related to a problem? Please describe

I have noticed that there is a space for improvement as of ARIA functionality.

Describe the solution you'd like

Investigate possible places and add aria roles and attributes/labels. Consider alignment with Podman Desktop.
Look at ie. MainPage -> dividing into header and content as regions with labels. Then breaking down to the more specialized pages like, Recipes, Running, Catalog, Services, Playground and eventually into the most detailed pages like start Recipe details -> Start Recipe, Model details, Service Details, etc.

Describe alternatives you've considered

No response

Additional context

No response