inotify: read_interfaces: add vlan-id and vlan-raw-device on dot notation vlan interfaces

inotify: read_interfaces: add vlan-id and vlan-raw-device on dot notation vlan interfaces

Setting the vlan-id and vlan-raw-device value for vlan devices that
follow the dot notaton (interface.vlan) aligns how dot notation vlan
devices and vlan devices that use the explicit vlan-id and
vlan-raw-device options, available with ifupdown2, are represented in
API return values.

Previously the type for both was 'vlan' but only the latter showed more
details.

Setting these values here should not have any influence on how the
interfaces file is being written as these two values are already
filtered in __write_etc_network_interfaces for dot notation devices.

Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>