#81: Improved path matching to support partial-part params

The current implementation does path matching assuming that a path param occupies a whole path part, e.g. /foo/{param}/bar

This PR improves the matching to support params that are only part of a path part, e.g. /foo/{param}.json or /foo/{param1}-{param2}

I also split apart the concepts of NormalizedPath and ApiPath to pull all of the templating logic to where it should belong. This led to some simplification of the operation resolution logic.