The primary purpose of this is to split out the handling of the native
libs. This is a consequence of using ProjectReference, and resolves the
following issues:
1. When compiling for iOS, it really doesn't like multiple files being
included in the same output path. Example: all Windows SDL.dll files
placed as SDL.dll in the output path.
2. Even if (1) was somehow resolved, the iOS build also doesn't like the
linux-specific .so files being included.
3. As a consequence of (1), it's likely that the project already doesn't
work on some configurations. For example, because win-x86 is
specified as the last item, it will likely take precedence over all
other versions.
4. It looks like `RuntimeIdentifier` is not project-transitive, against
my expectations. I really want the project to both select the correct
single native lib for the current platform, and also support
compiling with a RID (`dotnet build -r ...`).
So now we only copy the correct lib to the output path, and don't do it
while packaging (not required).
Dan Balasescu