Extend vlan group scopes

[kovalev94]

I think it wil be very helpful if Netbox will have this abilities with vlan groups:

Ability to choose several scope types.
Ability to choose several scopes in one type.

Also i think it wil be cool if we will have device role scope type in vlan groups scope.

I will provide example as an ISP.
I have 3 site groups: Home sites(for access switches), Trunk node sites (for aggregation switches) and CORE sites( for core hardware)
With current scope settings i cant assign vlan group for trunk node sites and core sites both. I have vlans which should be assigned for aggregation switches and core hardware, but shouldn't be assigned to access switches.
Also i may want to assign vlan only for switches, but not for other network hardware installed on sites.
Ability to choose several scopes types and scopes will add more flexibility for vlan assigment and solve cases like examples.