[sim] Move Sim classes from HAL to wpilibc/j (#2549)

Also move some things in HAL for consistency.

WAS:
C++:
- C APIs: #include "mockdata/AccelerometerData.h"
- User side class: #include "simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.sim.mockdata.AccelerometerData (and a few classes in hal.sim)
- User side classes: hal.sim.AccelerometerSim

IS:
C++:
- C APIs: #include "hal/simulation/AccelerometerData.h"
- C++ class: #include "frc/simulation/AccelerometerSim.h"
Java:
- JNI APIs: hal.simulation.AccelerometerData
- User side class: wpilibj.simulation.AccelerometerSim

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

@@ -0,0 +1,72 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) 2019-2020 FIRST. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#pragma once
+
+#include <memory>
+#include <utility>
+
+#include <hal/simulation/DutyCycleData.h>
+
+#include "CallbackStore.h"
+
+namespace frc {
+namespace sim {
+class DutyCycleSim {
+ public:
+  explicit DutyCycleSim(int index) { m_index = index; }
+
+  std::unique_ptr<CallbackStore> RegisterInitializedCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelDutyCycleInitializedCallback);
+    store->SetUid(HALSIM_RegisterDutyCycleInitializedCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  bool GetInitialized() const {
+    return HALSIM_GetDutyCycleInitialized(m_index);
+  }
+
+  void SetInitialized(bool initialized) {
+    HALSIM_SetDutyCycleInitialized(m_index, initialized);
+  }
+
+  std::unique_ptr<CallbackStore> RegisterFrequencyCallback(
+      NotifyCallback callback, bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelDutyCycleFrequencyCallback);
+    store->SetUid(HALSIM_RegisterDutyCycleFrequencyCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  int GetFrequency() const { return HALSIM_GetDutyCycleFrequency(m_index); }
+
+  void SetFrequency(int count) { HALSIM_SetDutyCycleFrequency(m_index, count); }
+
+  std::unique_ptr<CallbackStore> RegisterOutputCallback(NotifyCallback callback,
+                                                        bool initialNotify) {
+    auto store = std::make_unique<CallbackStore>(
+        m_index, -1, callback, &HALSIM_CancelDutyCycleOutputCallback);
+    store->SetUid(HALSIM_RegisterDutyCycleOutputCallback(
+        m_index, &CallbackStoreThunk, store.get(), initialNotify));
+    return store;
+  }
+
+  double GetOutput() const { return HALSIM_GetDutyCycleOutput(m_index); }
+
+  void SetOutput(double period) { HALSIM_SetDutyCycleOutput(m_index, period); }
+
+  void ResetData() { HALSIM_ResetDutyCycleData(m_index); }
+
+ private:
+  int m_index;
+};
+}  // namespace sim
+}  // namespace frc