cubicweb #2559931 json_dumps(entity) is unpredictable [validation pending]

It depends on the contents of the attribute cache, leading to workarounds in the ejsonexport view.

prioritynormal
typebug
done in3.17.0
load1.000
load left0.000
closed by#353bbd17a8b6 Improve entity json export (closes #2559931)
patchentity: make __json_encode__ predictable (closes #2559931) [rejected]