Add test assets for WMF to PNG conversion test

[safern]

These assets are needed for: dotnet/runtime#35169

[ViktorHofer]

Where are those assets coming from? What's their license? :)

[tannergooding]

Do we have a NuGet package or somewhere we can add this to instead? Generally speaking, checking binary files into git isn't "best practice"...

If we are going to check them in, do we expect they will ever need to be removed or modified and if so, how frequently?

[ViktorHofer]

This repository's purpose is to generate nuget packages which are then consumed in dotnet/runtime.

[tannergooding]

This repository's purpose is to generate nuget packages which are then consumed in dotnet/runtime.

I completely missed the -assets part of the name. My bad 😄

[safern]

Where are those assets coming from? What's their license? :)

Those are just dummy images a internal costumer shared with me for the repro and said it was fine to put them in GH.