Add a sample of sparse packaged Winforms using WCR

[ssparach]

Description

This pull request includes sample code demonstrating how to invoke WCR APIs within a Windows Forms application (sparse packaged). The application performs text recognition and summarization of text on an image after displaying package information.

Target Release

The example currently targets the 1.7-experimental3 which contains the WCR API. However, this will be updated in the future to target the stable release when it becomes available.

Checklist

Note that /azp run currently isn't working for this repo.

• Samples build and run using the Visual Studio versions listed in the Windows development docs.
• Samples build and run on all supported platforms (x64, x86, ARM64) and configurations (Debug, Release).
• Samples set the minimum supported OS version to Windows 10 version 1809.
• Samples build clean with no warnings or errors.
• [For new samples]: Samples have completed the sample guidelines checklist and follow standardization/naming guidelines.
• Microsoft employees only: you can validate your changes by following the instructions here: https://www.osgwiki.com/wiki/WindowsAppSDK-Samples

[codendone]

Looks great! Added a few small comments.

[codendone]

Is this "Find an end" code an effort to fix the process hang issue you mentioned? I wouldn't expect this to be needed.

[ssparach]

Yes, there were instances when I could click 'exit' on the main form even though everything else was unresponsive and hanging. Hence, I added code in the dispose method to ensure the process ends if possible.

[codendone]

I could maybe understand killing/exiting the current process, but finding and killing other processes seems weird.

I wondered if this code may have been added due to the extra run code which you've now removed, but the symptom you described sounds different.

[ssparach]

Thinking about this a bit more, I am inclined to remove this for now. I will revisit later if the sample application persistently continues to hang and will make a note to verify this when samples will be updated to the stable release. Thanks!