[mlir][sparse] export sparse tensor runtime support through header file

Exposing the C versions of the methods of the sparse runtime support lib
through header files will enable using the same methods in an MLIR program
as well as a C++ program, which will simplify future benchmarking comparisons
(e.g. comparing MLIR generated code with eigen for Matrix Market sparse matrices).

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D91316