Add support for Endpoints 2.0 Parameters (#1953)

* Add support for Endpoints 2.0 Parameters

This commit adds `EndpointDecorator` which injects Endpoint
parameters in to the operation property bag. These can come from
an ordered list of sources—this wires them all up. To facilitate
testing, this diff also writes the parameters into the property
bag during operation generation.

* remove println

* CR Feedback