* remove the baseurl from the JMAP client configuration, and pass it to
the session retrieval functions instead, as that is really the only
place where it is relevant, and we gain flexibility to discover that
session URL differently in the future without having to touch the
JMAP client
* move the default account identifier handling from the JMAP package to
the Groupware one, as it really has nothing to do with JMAP itself,
and is an opinionated feature of the Groupware REST API instead
* add an event listener interface for JMAP events to be more flexible
and universal, typically for metrics that are defined on the API
level that uses the JMAP client
* add errors for when default accounts cannot be determined
* split groupware_framework.go into groupware_framework.go,
groupware_request.go and groupware_response.go
* move the accountId logging into the Groupware level instead of JMAP
since it can also be relevant to other operations that might be
worthy of logging before the JMAP client is even invoked
* implement correct Etag and If-None-Match handling, responding with
304 Not Modified if they match
* introduce SessionState and State string type aliases to ensure we are
using the correct fields for those, respectively
* extract the SessionState from the JMAP response bodies in the
groupware framework instead of having to do that in every single
groupware API
* use uint instead of int in some places to clarify that the values are
>= 0
* trace-log how long a Session was held in cache before being evicted
* add Trace-Id header handling: add to response when specified in
request, and implement a custom request logger to include it as a
field
* implement a more compact trace-logging of all the methods and URIs
that are served, to put them into a single log entry instead of
creating one log entry for every URI
* after having decided that the Groupware API should be a standalone
independent custom REST API that is using JMAP data models as much as
possible,
* removed Groupware APIs from the Graph service
* moved Groupware implementation to the Groupware service, and
refactored a few things accordingly
