Update nuget icon

[shweaver-MSFT]

Fixes #144

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

The nuget icon is missing from the published preview packages on Nuget.

What is the new behavior?

I used WCT as a reference to update the property and targets files for the solution and add the icon.

I also noticed that after this change, the GraphPresenter was having a tough time deserializing some types, so I converted it from Newtonsoft Json to System.Text.Json as well to fix up the errors.

PR Checklist

Please check if your PR fulfills the following requirements:

• [ ] Tested code with current supported SDKs
• [ ] 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

Other information

[ghost]

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

[shweaver-MSFT]

Tested in ContosoNotes and the nuget image shows up as expected when using the WCT PRs feed.