* move ContactCard from jscontact to jmap, as it is actually a JMAP
specification item, but also was causing too many issues with
circular references from jscontact -> jmap
* introduce Foo, Idable, GetRequest, GetResponse, etc... types and
generics
* first attempt at a Foo factory type for Mailboxes, needs to be
expanded to further minimize repetition
* add more specialized template functions to avoid repetition
* introduce ChangesTemplate[T] for *Changes structs
* add example generator infrastructure, with some examples for pkg/jmap
and pkg/groupware, with more needing to be done
* alter the apidoc Makefile to stop using go-swagger but, instead, use
the openapi.yml file that must be dropped into that directory using
groupware-apidocs (will improve the integration there later)
* add Makefile target to generate examples
* bump redocly from 2.4.0 to 2.14.5
* introduce Request.PathParam() and .PathParamDoc() to improve API
documentation, as well as future-proofing
* improve X-Request-ID and Trace-Id header handling in the middleware
by logging it safely when an error occurs in the middleware
