[mlir][sparse] Factoring out NewCallParams class in SparseTensorConversion.cpp

The new class helps encapsulate the arguments to `_mlir_ciface_newSparseTensor` so that client code doesn't depend on the details of the API.  (This makes way for the next differential which significantly alters the API.)

Reviewed By: aartbik

Differential Revision: https://reviews.llvm.org/D137680