add the loopback device type and additional flags

[exit91]

This commit fixes in particular the example from the README, which errors (with the message Error: Unsupported Type) due to not recognising the loopback device type.

Proposed Changes

• added entries for DeviceInterfaceFlag according to https://github.com/NetworkManager/NetworkManager/blob/main/src/libnm-core-public/nm-dbus-interface.h#L1243-L1252
• added entry for DeviceType according to https://github.com/NetworkManager/NetworkManager/blob/main/src/libnm-core-public/nm-dbus-interface.h#L241-L275
• added entry for ActivationStateFlag according to https://github.com/NetworkManager/NetworkManager/blob/main/src/libnm-core-public/nm-dbus-interface.h#L1070-L1081

[friedow]

Works for me :+1:. Can you merge and release this please :)?

[truehumandesign]

Works for me 👍. Can you merge and release this please :)?

Done 👍