message: Use fontCache lookup to remove access to global MAIN_FONT
diff: #include <algorithm>
  extern NAS2D::Point<int> MOUSE_COORDS;
  -extern const NAS2D::Font* MAIN_FONT; /// yuck
  extern std::string CURRENT_LEVEL_STRING;
  @@ -35,7 +34,8 @@ void MapViewState::drawSystemButton() const
  // Turns
  const auto turnImageRect = NAS2D::Rectangle{128, 0, constants::ResourceIconSize, constants::ResourceIconSize};
  renderer.drawSubImage(mUiIcons, position, turnImageRect);
  - renderer.drawText(*MAIN_FONT, std::to_string(mTurnCount), position + textOffset, NAS2D::Color::White);
  + const auto* font = &fontCache.load(constants::FONT_PRIMARY, constants::FontPrimaryNormal);
  + renderer.drawText(*font, std::to_string(mTurnCount), position + textOffset, NAS2D::Color::White);
  position = mTooltipSystemButton.rect().startPoint() + NAS2D::Vector{constants::MarginTight, constants::MarginTight};
  bool isMouseInMenu = mTooltipSystemButton.rect().contains(MOUSE_COORDS);
  