Add ability to set Msbuild properties for design time

### Details

Should add ability to change the global properties we pass to design time loading.

Old proof of concept in #1065

### Checklist

- [x] I have looked through existing issues to make sure that this feature has not been requested before
- [x] I have provided a descriptive title for this issue
- [x] I am aware that even valid feature requests may be rejected if they do not align with the project's goals
- [x] I or my company would be willing to contribute this feature