[mlir][NFC] Refactor linalg substituteMin and AffineMinSCF canonizalizations

Break up the dependency between SCF ops and substituteMin helper and make a
more generic version of AffineMinSCFCanonicalization. This reduce dependencies
between linalg and SCF and will allow the logic to be used with other kind of
ops. (Like ID ops).

Differential Revision: https://reviews.llvm.org/D100321