Thinking more about how to know what to resolve and what not to means depending on circular reference knowledge. So using an idea from @TristanSpeakEasy, the `*resolver.ResolvingError` now contains a pointer to the original circular error, and it also implements the `Error` interface correctly which allows it simple passage up the chain, without losing fidelity.
Added new documentation example as well
Signed-off-by: Dave Shanley <dave@quobix.com>
Building out models that have circular references is tricky. Particularly when they are polymorphic ones. The resolver now searches the polymorphic references for circular references as well (which is returning much more valuable results now). The low level model is now sensitive to this and will avoid building out anything that is circular.
