Add an option to restrict the number of tenants a user can create

@yas, please review this patch. This adds a permission to restrict users from adding multiple tenants. By default, users cannot add more than one tenant.

The following permission needs to be checked to all users to add multiple tenants.

@balwinlouie

Thank you for the patch. It looks good basically, I posted my comments. Thanks

@yas, please review the updated PR.

@baldwinlouie

Thank you for the update. It looks good to me now. I'll merge the patch to 1.0.x, and close this issue as Fixed.

Automatically closed - issue fixed for 2 weeks with no activity.