feat: Add scriptor access flag

[phorward]

• Adds access flag scriptor
• Documentation for the default access flags and the default roles
• User default access flag with scriptor for users having the admin-role

[sveneberth]

Well, the new roles are okay for me. But where do we use them? You didn't change a can* method of a module/prototype 🤔

[phorward]

Well, the new roles are okay for me. But where do we use them? You didn't change a can* method of a module/prototype 🤔

You're right. My initial intention behind this was to display the "scriptor"-button in the Admin. I will have further consideration about this and let you know.

The base branch was changed.

[Grashalmbeisser]

There needs to be an distinction between a Flag and an Access right. Since "Scriptor" is not an Acces right but a usage privillege we should differentiate that as a flag not as a right.

[phorward]

Upated this PR in convenience with @akelch. Clarified naming convention, so an access flag is something like "root", "admin" or now "scriptor", and an access-right is the stuff with the "add", "edit", "delete", "view" or any other action-related.