[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

hal/src/main/native/sim/DriverStation.cpp

@@ -21,8 +21,8 @@
 #include <wpi/raw_ostream.h>
 
 #include "HALInitializer.h"
+#include "hal/simulation/MockHooks.h"
 #include "mockdata/DriverStationDataInternal.h"
-#include "mockdata/MockHooks.h"
 
 static wpi::mutex msgMutex;
 static wpi::condition_variable* newDSDataAvailableCond;