[mlir][taco] Uses sparse_tensor.new to read tensor input data from files.

Replace the Python implementation for reading tensor input data from files with
create_sparse_tensor that uses sparse_tensor.new.

The MLIR TNS format has two extra meta data lines. Add the extra meta data to a
test data file.

Implement TACO tensor methods evaluate and unpack.

Add unit tests.

Reviewed By: aartbik

Differential Revision: https://reviews.llvm.org/D118803