[MLIR][Affine][VectorOps] Utility to vectorize loop nest using strategy

This patch adds a utility based on SuperVectorizer to vectorize an
affine loop nest using a given vectorization strategy. This strategy allows
targeting specific loops for vectorization instead of relying of the
SuperVectorizer analysis to choose the right loops to vectorize.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D85869