Mesh node output parameters

[pow2clk]

Need to be allowed for this launch mode and no others. SROA components.

Is your feature request related to a problem? Please describe.
Mesh nodes require mesh shader type outputs to pass along the results to the usual mesh shader interface.

Describe the solution you'd like
Leverage existing code paths in the compiler to allow output indices, vertices, and primitives to be output just as they are in mesh shaders.

ensure that assigning of these outputs forces the inclusion of SetMeshOutputCounts() just as it does in mesh shaders

Additional context
subtask of #6404