Add Linux WI-FI state support

Support monitoring WIFI state on Linux through:
- NetworkManager (D-Bus)
- IWD (D-Bus)
- wpa_supplicant (control socket)
- ConnMan (D-Bus)

experimental/libbox/platform/interface.go

@@ -18,6 +18,7 @@ type Interface interface {
 	UnderNetworkExtension() bool
 	IncludeAllNetworks() bool
 	ClearDNSCache()
+	UsePlatformWIFIMonitor() bool
 	ReadWIFIState() adapter.WIFIState
 	SystemCertificates() []string
 	process.Searcher