Transition UWP builds to native toolchain

[sync-by-unito[bot]]

Currently our UWP test app is compiled to IL which at runtime is fed to the JIT compiler.(standard .NET toolchain). In real life (store submission), a UWP app built in release is built straight into "machine code". We should test our SDK against UWP app built straight into machine code. The feature it's called .NET native.

[sync-by-unito[bot]]

➤ Nikola Irinchev commented:

Unlinking from the CI modernization project as this is going to be blocked on NUnit supporting UWP Native.

[sync-by-unito[bot]]

➤ Andrea Catalini commented:

This issue is blocked on the resolution of this an issue with the support for NUnit in UWP native