[mlir][bufferization] Improve buffer deallocation pass

Add a new Buffer Deallocation pass replacing the old one with the goal of
inserting fewer clone operations and supporting additional use-cases.
Please refer to the Buffer Deallocation section in the updated
Bufferization.md file for more information on how this new pass works.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D158421