Gateway usage reporting is set to gateway ID but it need to have an extension

When gateway usage reporting is enabled in the SciGaP portal for each resource, in individual gateway need to add the "Gateway Id for Usage Reporting"

gateways have added the gateway ID for each but just the gateway ID is not sufficient for correct reporting. It need to have an extension. We should provide the gateway admins with a comment to mention that a extension is required. If not this will be forgotten and there is no way to validate either.

It would be ideal if a check can be enforced to check the existing of an extension. similar to checking email format.