Automatictically identify triggers that do not match schema

This is a next step towards proactive schema validation:

In order to understand differences between the current database schema of an installation and the desired and expected schema, we'd like to create tooling around schema validation. In this step, we're going to build the basic framework and only implement trigger validation.

Index validation consists of comparing the list of available triggers, and their exact definition against the desired schema.

In this iteration, it'll be enough to have a rake task to run schema validation that reports back any differences (for triggers) in a summary-like fashion.