configuration: add option to select network interface

This commit renames the "Services" tab to "Network" and adds a combobox that allows the user to select the network interface that yuzu should use. This new setting is now used to get the local IP address in Network::GetHostIPv4Address. This prevents yuzu from selecting the wrong network interface and thus using the wrong IP address. The return type of Network::GetHostIPv4Adress has also been changed.