[mlir][tensor][linalg] Add a pattern that generalizes tensor.pack op.

The pattern generalizes a tensor::PackOp into a sequence of tensor +
Linalg ops, when the outer dims are all 1s. It uses the trick of
rank-reduced tensor.extract_slice to get the tile; transpose the tile;
use tensor.insert_slice to insert it to the destination of inner tile.

Reviewed By: pifon2a, tyb0807

Differential Revision: https://reviews.llvm.org/D140060