[hal] Consistently use .hpp for C++ header content

Some headers were renamed, but others were split.

hal/src/main/native/sim/HALInternal.hpp

@@ -0,0 +1,19 @@
+// 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 <stdint.h>
+
+#include <string_view>
+
+namespace wpi::hal {
+void SetLastError(int32_t* status, std::string_view value);
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
+                                 int32_t minimum, int32_t maximum,
+                                 int32_t channel);
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
+                                     int32_t channel,
+                                     std::string_view previousAllocation);
+}  // namespace wpi::hal