[FEATURE] Add "group by" setting to per document monitor

[ghost]

Is your feature request related to a problem?
No, it is not a problem

What solution would you like?
Group by occurences of specific keywords/fields just like in per bucket monitor and also add as table column in the alerts table.
Also list all of the findings in one overview.

What alternatives have you considered?
per bucket monitor but it does not have all document findings

[ghost]

@AWSHurneyt is this something which could be implemented in the near future or is it rather low prio?