Progressbar Updates

[robloo]

What does the pull request do?

In auditing ProgressBar for #9944 it was found to be a very outdated control. Two things really needed to be fixed:

1. Comments added (where I knew what they should be)
2. TemplateProperties renamed to TemplateSettings which is the modern convention and used in other controls like SplitView.

This PR fixes those two issues.

The single DirectProperty Percentage is already correct as a read-only calculated property so wasn't changed. All DirectProperty usage in the template settings class was ignored as out-of-scope (animation-related properties are being skipped anyway).

What is the updated/expected behavior with this PR?

See above

How was the solution implemented (if it's not obvious)?

See code

Checklist

• Added unit tests (if possible)?
• Added XML documentation to any related classes?
• Consider submitting a PR to https://github.com/AvaloniaUI/Documentation with user documentation

Breaking changes

Yes, for styles renamed ProgressBarTemplateProperties to ProgressBarTemplateSettings. This needed to be done for 11.0 API finalization anyway. Style and control libraries will need to update.

Obsoletions / Deprecations

None

Fixed issues

Fixes #10707

[avaloniaui-team]

You can test this PR using the following package version. 11.0.999-cibuild0034087-beta. (feed url: https://pkgs.dev.azure.com/AvaloniaUI/AvaloniaUI/_packaging/avalonia-all/nuget/v3/index.json) [PRBUILDID]