cubicweb-company #2487293 upgrade to cw 3.15 API [validation pending]

prioritynormal
typeenhancement
done in0.6.0
load left0.000
closed by#1d683451c2db [entities] s/fetch_order/cw_fetch_order/ to silence warning from cw 3.14 (closes #2487293), #99558af03c17 cw 3.15 api update. Closes #2487293
patch[entities] s/selectors/predicates/ to silence warning from cw 3.15 (part of #2487293) [applied]