OSF: Used model.NewPointer everywhere (#27838)

```release-note
NONE
```

server/public/model/outgoing_oauth_connection_test.go

@@ -18,8 +18,8 @@ func newValidOutgoingOAuthConnection() *OutgoingOAuthConnection {
 		Name:                "Test Connection",
 		ClientId:            NewId(),
 		ClientSecret:        NewId(),
-		CredentialsUsername: NewString(NewId()),
-		CredentialsPassword: NewString(NewId()),
+		CredentialsUsername: NewPointer(NewId()),
+		CredentialsPassword: NewPointer(NewId()),
 		OAuthTokenURL:       "https://nowhere.com/oauth/token",
 		GrantType:           OutgoingOAuthConnectionGrantTypeClientCredentials,
 		CreateAt:            GetMillis(),