MM-45535: Batch optimize auth checks in GraphQL (#20634)

We create two new auth checks which take multiple channels
and teams. They can be used to check whenever a user needs
access to multiple entities.

These are then access in dataloaders to ease the load in the
database.

```release-note
NONE
```

model/session.go

@@ -147,9 +147,9 @@ func (s *Session) AddProp(key string, value string) {
 }
 
 func (s *Session) GetTeamByTeamId(teamId string) *TeamMember {
-	for _, team := range s.TeamMembers {
-		if team.TeamId == teamId {
-			return team
+	for _, tm := range s.TeamMembers {
+		if tm.TeamId == teamId {
+			return tm
 		}
 	}