[mlir] provide a base class for transform interpreter passes

[mlir] provide a base class for transform interpreter passes

The transform dialect infrastructure does not provide a default
interpreter pass and instead expects users to create their own to ensure
all relevant extensions and dependent dialects are loaded. Provide a
base class for implementing such passes that includes the additional
facilities for debugging and is aware of the multithreaded nature of
pass execution.

Reviewed By: pifon2a, nicolasvasilache

Differential Revision: https://reviews.llvm.org/D142729