WIP: all: support bridge vlan ranges
In some cases it is convenient to specify ranges of bridge vlans, as already supported by iproute2 and natively by kernel. With this commit it becomes possible to add a range in this way:
nmcli connection modify eth0-slave +bridge-port.vlans "100-200 untagged"
vlan ranges can't be PVIDs because only one PVID vlan can exist.