* upgrade Stalwart image for devtools/full to 0.14.1
* re-assert which features are implemented or not in 0.14.1
* refactor the integration tests yet again to make it clearer and
easier to see those "features-or-not"
* get rid of old tests that are now better covered by integration tests
* rewrite how we compare expected and actual objects in integration
tests, finally having found a way to ignore the @type attribute
properly instead of having to mutate all objects to remove it
