[SIEM] [Case] API To Dos

[stephmilovic]

• enhance all user fields to include email when available

• store user information about who edited what field or comment and when . A "user action saved object"

• enhance get_cases response to include commentCount

• updated_by field added to Case and Comment

• closed_at field add to closed Case

• add getCurrentUser call to the api or return in some other way

• endpoint that returns participants. same way we scrape up tags but from our new "user action saved object"?

• allow comment and case POST routes to take an id query param to PATCH

• endpoint that returns all Reporters (to sort All Cases table)

• Make comment field mandatory and not optional on patch comment route Code

[elasticmachine]

Pinging @elastic/siem (Team:SIEM)