Set initial focus for supervisor dialogs

[steverep]

Proposed change

Dialog Module	Initial Focus	Notes
dialog-hassio-backup-upload	Close button
dialog-hassio-backup	First radio or checkbox
dialog-hassio-create-backup	Name field
dialog-hassio-datadisk	Combobox or cancel button
dialog-hassio-hardware	Search field
dialog-hassio-markdown	ha-markdown	I don't know how to invoke this one to test. It needs a focus method.
dialog-hassio-network	First tab or radio
dialog-hassio-registries	Add button or form when adding	Focus on ha-form doesn't transfer. I'll fix that in separate PR.
dialog-hassio-repositories	Add URL field

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

Additional information

• This PR fixes or closes issue: Modal dialogs need keyboard focus management #10754
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.