Added knob fot user buffer/tensor parallel communication overlap for …
…MCORE pass

# What does this PR do ?

Added a knob to pass from the Nemo Launcher to the Mcore pass model for the ub_tp_comm_overlap switch.

Reference PR: https://github.com/NVIDIA/Megatron-LM/pull/532
This fix will be used by this PR in the Megatron-LM repository.