[Canonicalize] Fully parameterize the pass based on config options. NFC.

This allows C++ clients of the Canonicalize pass to specify their own
Config option struct to control how Canonicalize works, increasing reusability.

This also allows controlling these settings for the default Canonicalize pass
using command line options.  This is useful for testing and for playing with
things on the command line.

Differential Revision: https://reviews.llvm.org/D103069