Set initial focus for some more dialogs

[steverep]

Proposed change

Dialog Module	Initial Focus
dialog-add-user	Name or user field
dialog-system-log-detail	Log entry
dialog-statistics-fix-units-changed	Radio
dialog-statistics-fix-unsupported-unit-meta	Fix button
dialog-config-entry-system-options	First checkbox
dialog-mqtt-device-debug-info	First checkbox

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.