Co-authored-by: Jesse Grabowski <48652735+jessegrabowski@users.noreply.github.com>

- newaxis is handled as explicit DimShuffel on the inputs
- slices are encoded internally, so the Ops only take numerical inputs
Co-authored-by: Ricardo Vieira <28983449+ricardov94@users.noreply.github.com>

They would be silently ignored otherwise

Extend the implementation of csr_matrix and csc_matrix in numba. Use those implementations in SparseFromDense

Make sure we don't issue unexpected warnings

Numba sparse: handle dot product between matrices more granularly to reduce the number of of format conversions