[DialogHeader] Allow dialog title exclusion from tab index

[NataschaZorgWijnhoven]

Pull Request

📖 Description

No possibility to exclude the dialog title from the tab index. The FluentDialogHeader provides a default tabindex of 0 which could not be overwritten.
Repro:

Now it is possible to mark to mark the new parameter ExcludeFromTabFocus with "true", thus changing this tabindex to -1.
This results in the behaviour of the tab being skipped.
Repro:

🎫 Issues

👩‍💻 Reviewer Notes

📑 Test Plan

✅ Checklist

General

• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have added Unit Tests for my new component
• I have modified an existing component
• I have validated the Unit Tests for an existing component

⏭ Next Steps

[NataschaZorgWijnhoven]

@microsoft-github-policy-service agree company="Quadira"

[dvoituron]

This tabindex=“0" attribute is present to avoid displaying the ’Close” tooltip when the dialog box is open. You can see this in your second example.

[vnbaaij]

@NataschaZorgWijnhoven I'm seeing build errors in the pipelines (not finding CssBuilder/StyleBuilder). Can you check locally and correct?