Ability to restrict portal customers issue creation with permissions or groups

Problem Definition

Sometimes it would be good to restrict certain customers from creating tickets and only allow them to view, essentially a read-only user.

Currently, you can only allow all Service Desk Customers - portal only user from the permission scheme

Suggested Solution

Add a permission or group available to customers so administrators can restrict some customers from creating tickets

Workaround

Not very manageable for a large amount of customers:

1. Add individual customers who should be allowed to create tickets as single users to a non-applicable permission like 'Edit Own Worklogs' or anything they have no use for.
2. Update workflow create transition validator to Only users with Edit Own Worklogs permission can execute this transition.