BitmapIconSource extension

[Sergio0694]

Follow up for #3110 and #3129

PR Type

What kind of change does this PR introduce?

• Feature
• Refactoring (no functional changes, no api changes)

What is the current behavior?

There was no extension for BitmapIconSource.
Also the SymbolIcon were using the wrong name for the Glyph property.

What is the new behavior?

• Added a new BitmapIconSource extension
• Changed the Glyph property to Symbol when using the Symbol type. This follows the naming of the actual original SymbolIcon class from UWP.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• Pull Request has been submitted to the documentation repository instructions. Link:
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes

[ghost]

Thanks Sergio0694 for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌

[marcelwgn]

[michael-hawker]

This was an oversight on a missing API for completeness found during our doc review here, which we should have gotten to a bit sooner outside of our other circumstances.

I think this is a good improvement to make now vs. later, and we've got a bit more stabilization time now too.

Will commit PR as we have @chingucoding's review as well, thanks for jumping in! 🦙❤