[wpigui] Add GetDistSquared and MaxFit functions

These utility functions were moved from halsim_gui.

simulation/halsim_gui/src/main/native/include/GuiUtil.h

@@ -1,24 +0,0 @@
-/*----------------------------------------------------------------------------*/
-/* Copyright (c) 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 <imgui.h>
-
-namespace halsimgui {
-
-// get distance^2 between two ImVec's
-inline float GetDistSquared(const ImVec2& a, const ImVec2& b) {
-  float deltaX = b.x - a.x;
-  float deltaY = b.y - a.y;
-  return deltaX * deltaX + deltaY * deltaY;
-}
-
-// maximize fit while preserving aspect ratio
-void MaxFit(ImVec2* min, ImVec2* max, float width, float height);
-
-}  // namespace halsimgui