cubicweb-datacat #5553403 improve display of distribution entities within a dataset [validation pending]

move this information in a dedicated tab reachable from dataset primary view, in particular

prioritynormal
typeenhancement
done in0.3.0
load0.500
load left0.000
closed by#24db7960667f [views] Display Dataset's distributions in a dedicated tab
patch[views] Display Dataset's distributions in a dedicated tab [applied]