MM-45120: Track team join times. Add API to retrieve new team members since a given time. (#20708)

* MM-45120: Starts tracking team join time. Adds API to retrieve team members who joined after a given time.

* MM-45120: Updates json casing to match model.User.

store/timerlayer/timerlayer.go

@@ -8072,6 +8072,22 @@ func (s *TimerLayerTeamStore) GetMembersByIds(teamID string, userIds []string, r
 	return result, err
 }
 
+func (s *TimerLayerTeamStore) GetNewTeamMembersSince(teamID string, since int64, offset int, limit int) (*model.NewTeamMembersList, int64, error) {
+	start := time.Now()
+
+	result, resultVar1, err := s.TeamStore.GetNewTeamMembersSince(teamID, since, offset, limit)
+
+	elapsed := float64(time.Since(start)) / float64(time.Second)
+	if s.Root.Metrics != nil {
+		success := "false"
+		if err == nil {
+			success = "true"
+		}
+		s.Root.Metrics.ObserveStoreMethodDuration("TeamStore.GetNewTeamMembersSince", success, elapsed)
+	}
+	return result, resultVar1, err
+}
+
 func (s *TimerLayerTeamStore) GetTeamMembersForExport(userID string) ([]*model.TeamMemberForExport, error) {
 	start := time.Now()