Enable insight to action grouping options

As of today, insight to action can only trigger case-id based alerts (1 case-id triggers 1 action, mail etc...).

It would be really useful to enable the possibility to select another field to group case-id for example by responsible (person or department). End-user will then receive an overview with a table listing all the case-ids which are matching the condition instead of receiving as many e-mail (perceived as a polution) as there are cases.

If a grouping field is selected, mail content should include all case-ids (with payload content) as a table or as a concatenated list. Information should be displayed following the payload order.

Ideally, it should be possible to embed links (under a short label).