Make sure foo.ico,0 works as an icon specifier

### Windows Terminal version

1.21.3231.0

### Windows build number

10.0.19045.5198

### Other Software

_No response_

### Steps to reproduce

Change default PNG resource with any std Windows ICO resource and you get one behavior. Add ",0" at the end for another behavior. Both together would be correct as a whole. Individually, both are wrong.

[Screenshots](https://postimg.cc/gallery/pP9SHw6)

### Expected Behavior

Correct usage of the icon resource for the given place it's supposed to be displayed.

### Actual Behavior

Wrong or no icon displayed in taskbar jump list or in app.

Start by reproducing the issue on Windows Terminal 1.21.3231.0 with a standard Windows ICO resource, comparing the default PNG resource with the same resource followed by ",0". Done means the correct icon is displayed consistently in the taskbar jump list and in the app for both forms.

Written by the indexing model from the issue text.