[hal, wpilib] PWM Rewrite (#7845)

The HAL will only contain the output period and the raw microseconds. Higher level things such as SimDevice can handle everything else.

wpilibc/src/main/native/include/frc/simulation/ServoSim.h

@@ -0,0 +1,31 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#pragma once
+
+#include <hal/SimDevice.h>
+#include <units/length.h>
+
+#include "frc/Servo.h"
+
+namespace frc {
+
+class Servo;
+
+namespace sim {
+class ServoSim {
+ public:
+  explicit ServoSim(const Servo& servo);
+
+  explicit ServoSim(int channel);
+
+  double GetPosition() const;
+
+  double GetAngle() const;
+
+ private:
+  hal::SimDouble m_simPosition;
+};
+}  // namespace sim
+}  // namespace frc