QRhi autotests: Have to work around the lack of D3DCompile on WinRT (UWP)

There is no runtime compilation support in WinRT. Or rather, there is support for development purposes but such applications are not deployable.

In our CI we already see that attempting to compile HLSL at runtime will fail as D3DCompile() cannot be resolved on WinRT. So there the D3D11 backend can only consume bytecode that has been generated by fxc offline (which is done by running qsb with the -c argument on Windows).

Make it possible to survive on WinRT, by skipping the attempt to compile HLSL from source. (and fail the pipeline creation instead )

This means that the qrhi autotest has to be updated to include dx bytecode in its .qsb assets instead of HLSL source code.