Program Icon property must copy .ico file to project (2)

[sujitnayak]

Visual Studio Version: 16.10 P3 Main builds (31229.188.main on my machine)

Summary:
Adding program icon with new Project Properties UX has a different behavior than the previous UX as described in Actual Behavior section.

Steps to Reproduce:

1. Create WPF or Winforms project for .NET Core/.NET FX 5.0

2. Go to Project Properties -> Application -> Resources tab and add program icon.

Expected Behavior:
The .ico file gets copied to the project directory and ApplicationIcon property is written to project file with just the name of the .ico file

Actual Behavior:
The icon file does not get copied to project folder and the ApplicationIcon property written to project file is fully qualified path to the .ico file.

User Impact:
ClickOnce publish fails due to this breaking change as it expects the .ico file to be in the project directory.

[melytc]

For reference, this is the previous experience looks like:

And this is the new experience:

[drewnoakes]

See also #6457 for a very similar work item on a different property. I suspect the solution to each will look similar.