cubicweb #2837251 Clean API for notification [validation pending]

Sylvain suggest having a simple function notify_on_commit(session, view, viewargs=None).

prioritynormal
typeenhancement
done in3.17.0
load left0.000
closed by#f5b40b66d36e [notification] introduce an official `notify_on_commit` function
patch[notification] provide a proper notification api instead of replacing it by yet another clumsy one. Closes #2837251 [applied]