Fixed issue with BonusBox border color

-The issue was the MapRGBA that was executed for only the local player
and stored in a variable.
-Added an if to determine the owner and set the variable accordingly.
Moved creation of BonusBox texture

-Moved creation of BonusBox to RenderHelpers
-The function takes the SDL_Renderer, the SDL_Rect for the BonusBox, the
outer SDL_Color and the inner SDL_Color
-Added function Renderer::CreateBonusBoxTexture() that calls the above
function with parameters based on a BonusBox and returns the resulting
texture.