[FIX] web_kanban : resequence column and content by drag and dropping
[FIX] yaml tests: Set on_change keys not in view logger as debug instead of warning

This is related to commit d31faceb67fd87acaca00365dcfc28925b08a37f
(This is to avoid the runbot being yellow if on_change methods have extra keys in the returned value, this is not wrong, the web client will simply ignore them).