cubicweb #2497697 crash when trying to get 'page-size' property [validation pending]

when appobject comes from a db api connection, even though load_appobjects has been called and cw.web is available

prioritynormal
typebug
done in3.15.5
load0.100
load left0.000
closed by#7e5246889148 [dbapi] load_appobjects must attempt to load available cubicweb configurations to avoid error when some object use a persistent propery (CWProperty) defined there. Closes #2497697