wayland: Add dedupe logic to window geometry configuration Adds deduplication logic to ConfigureWindowGeometry() to avoid setting redundant backbuffer, viewport and surface opaque region dimensions. State is now only set when the window and/or backbuffer dimensions change. This repurposes the viewport rect to always hold the actual size of the window, which can differ from the SDL size if things are being scaled. The SDL_Rect was removed in favor of two ints, as the x/y members of the struct were never used, so they just wasted space. Since the internal variables always have the true window size, the width/height getter functions are no longer required and can be removed.