Add config to PrimTorch's nvFuser executor (#84482)
This PR adds `executor_parameters` keyword argument to `torch._prims.executor.execute`.
For now there are two knobs:
* `use_python_fusion_cache: bool = True` whether to use lru_cache when constructing fusion object or not.
* `allow_single_op_fusion: bool = True` whether to allow fusions with single callable
Behavior can be controlled by passing dict with custom specified values as `executor_parameters` argument.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84482
Approved by: https://github.com/jjsjann123, https://github.com/ngimel
