* Add machinery to enable numba caching of function pointers

* Numba cache for Cholesky

* Numba cache for SolveTriangular

* Numba cache for CholeskySolve

* Numba cache for solve helpers

* Numba cache for GECON

* Numba cache for lu_factor

* Numba cache for Solve when assume_a="gen"

* Numba cache for Solve when assume_a="sym"

* Numba cache for Solve when assume_a="pos"

* Numba cache for Solve when assume_a='tri'

* Numba cache for QR

* Clean up obsolete code

* Feedback

* More feedback

* Rename `cache_key_lit` -> `unique_func_name_lit`