Move relay drivers from common to controller

src/drivers/null.rs

@@ -0,0 +1,22 @@
+use crate::drivers::RelayDriver;
+use crate::errors::EmgauwaControllerError;
+
+pub struct NullDriver {
+	pub pin: u8,
+}
+
+impl NullDriver {
+	pub fn new(pin: u8) -> Self {
+		Self { pin }
+	}
+}
+
+impl RelayDriver for NullDriver {
+	fn set(&mut self, _value: bool) -> Result<(), EmgauwaControllerError> {
+		Ok(())
+	}
+
+	fn get_inverted(&self) -> bool {
+		false
+	}
+}