Extra option "Block Sites" in editing role

[24x7-beheer]

We have some rolles that aren't allowed to access some sites.
Now we have to allow all site 1 by 1 in a role.
If we have the option al Block a Site and the rest is allowed this will solve al problems

Describe the solution you'd like
Under Settings => Permissions Manager => Manage Roles => The role.
Then under Allowed Sites a new option Block Sites.
This will allows all site by default but Block all sites that are Selected.

Describe alternatives you've considered
Then under Allowed Clients a new option Block Clients.
This will allows all Clients by default but Block all Clients that are Selected.

Additional context
Add any other context or screenshots about the feature request here.

Thanks in advanced
Wernie

[janstalhut]

Duplicate? #2098 und #1885