Make about dialog content copyable

[Summon528]

Summary of the Pull Request

Make about dialog content copyable

References

PR Checklist

• Closes About dialog should have a copy button #1335
• CLA signed. If not, go over here and sign the CLA
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Detailed Description of the Pull Request / Additional comments

Wrap aboutText with a selectable text block.

Validation Steps Performed

[DHowett-MSFT]

This is awesome! Thanks!

Clever use of the IInspectable parameter. 😄

[DHowett-MSFT]

It's a ContentDialog whose Content is a boxed HSTRING. This makes it the TextBlock you're suggesting we set IsTextSelectionEnabled on.

[DHowett-MSFT]

(Terminal doesn't use .xaml files, which is something we know we need to fix, etc.)

[mdtauk]

It's a ContentDialog whose Content is a boxed HSTRING. This makes it the TextBlock you're suggesting we set IsTextSelectionEnabled on.

I asked the question, checked the code change, and saw the property being used. Can't normally understand C++ code, so I spoke before checking lol

(Terminal doesn't use .xaml files, which is something we know we need to fix, etc.)

Xaml Direct?