[mlir][Linalg] Add comprehensive bufferization support for subtensor (5/n)

This revision refactors and simplifies the pattern detection logic: thanks to SSA value properties, we can actually look at all the uses of a given value and avoid having to pattern-match specific chains of operations.

A bufferization pattern for subtensor is added and specific inplaceability analysis is implemented for the simple case of subtensor. More advanced use cases will follow.

Differential revision: https://reviews.llvm.org/D102512