Blazor CRUD scaffolding should include correct ARIA roles and attributes

[MackinnonBuck]

Overview

The "Create.razor" template (defined here and here) should generate ARIA roles/attributes for compatibility with screen readers.

There are currently two known accessibility issues with this template:

1. Screen readers don't announce when a field is required
2. Screen readers don't announce when a value for a required field is not provided

Proposed fixes

1. Conditionally add the aria-required="true" HTML attribute here if the associated model property is annotated with a RequiredAttribute
2. Add role="alert" to the <ValidationSummary /> here

Update: The same changes should also be applied to the Edit page.

[mkArtakMSFT]

Thanks @MackinnonBuck.
@vijayrkn this is accessibility related so it has to be fixed by .NET 9 GA. Mackinnon has provided the content above. Can you handle this from here please?

[deepchoudhery]

Yep should be done for .NET 9 GA