Add accessibility test cases for MR homepage

As part of [Phase 1] Accessibility tests for Dashboards that is aiming to add a11y checks to all dashboards' feature tests, Product Accessibility WG have already covered MR dashboard.

We should include additional test cases for action focused MR homepage.

When adding the tests make sure that:

• all elements rendered in view after a user interactions are triggered before calling be_axe_clean. This means drawers, modals etc. Axe engine is able to test only elements rendered in the viewport
• you include tests for all possible states of the view. It can mean setting up the test with all possible details and making sure all smaller UI elements that render under curtain conditions are preset. That will give you better coverage.
• this epic includes some general guidance: Include axe automated accessibility checks in feature tests