fix(ai): release horn when human driver takes over from AI

vehicle/horn.h

@@ -0,0 +1,24 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+// the horn controls of the cab, on the WarningSignal bits of the vehicle (1: low tone, 2: high tone)
+namespace horn {
+
+int const low{1};
+int const high{2};
+
+// the signal after the key or button of the Tone is pressed. a single lever for both tones, without
+// separate buttons for them, can't sound both tones at once
+int pressed(int Signal, int Tone, bool Singlelever);
+// the signal after the key or button of the Tone is released
+int released(int Signal, int Tone);
+
+} // namespace horn