Mm 30807 granular data retention scaffold (#16891)

create the necessary tables, models and APIs for the granular data retention policy feature

model/team.go

@@ -42,6 +42,7 @@ type Team struct {
 	LastTeamIconUpdate int64   `json:"last_team_icon_update,omitempty"`
 	SchemeId           *string `json:"scheme_id"`
 	GroupConstrained   *bool   `json:"group_constrained"`
+	PolicyID           *string `json:"policy_id" db:"-"`
 }
 
 type TeamPatch struct {