network: update nm_augogen, about ipv4 widget properties
network: refactor code, rename SessionKeyErrors to sessionErrors
network: refactor code, return error message in each logic setter
network: update logic setters of virtual key
network: refactor code, return error in logic setter
network: add utils func expandIpv6Address()
network: move getter and setter of virtual key to each field file
network: complete virtual key getter and setter for ipv6
network: update ensureFileExists(), could check file extension
network: update code about vpn
network: complete logic setter for openvpn
network: add ConnectionType dbus property
network: add initSettingFieldIpv6(), fix missing ipv6 field after openning a connection
network: fix file path check issue
network: refacor code
add setup code, Sconstruct