Changelog:
- Sync menu overhauled to allow for specific configurations per provider
- Provider sync now uses separate trait implementations for Providers so it is simpler to add support for new providers
- OpenVPN now uses generated config files per provider rather than serverlists, simplifying the code and allowing more shared code with Wireguard case
- Checks added that necessary tools are installed (openvpn, wireguard-tools, shadowsocks-libev, nmcli (if NetworkManager installed))
- Shadowsocks support added for Mullvad OpenVPN