[mlir] NFC: move DiagnosedSilenceableFailure to Utils in Transform dialect

It was originally placed in TransformInterfaces for convenience, but it
is really a generic utility. It may also create an include cycle between
TransformTypes and TransformInterfaces if the latter needs to include
the former because the former uses the failure util.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D140978