[mlir][sparse] Support packing external data into arbitrary sparse tensor encoding.

We previously only support packing two array (values and coordinates) into COO tensors.
This patch allows packing inputs into arbitrary sparse tensor format.

It also deletes the "implicit" data canonicalization performed inside sparse compiler,
but instead requires users to canonicalize the data before passing it to the sparse compiler.

Reviewed By: aartbik

Differential Revision: https://reviews.llvm.org/D150916