pipewire: transparent wrappers around info structs

Apply ref-struct pattern to the info structs (ModuleInfo,NodeInfo,PortInfo,...).

Applied for:

• pw_module_info (ModuleInfo)
• pw_link_info (LinkInfo)
• pw_node_info (NodeInfo)
• pw_port_info (PortInfo)
• pw_client_info (ClientInfo)
• pw_device_info (DeviceInfo)
• pw_factory_info (FactoryInfo)