Address performance of drawing with transparency

[Devin-Mix]

Currently, alpha drawing of the GUI is using the PyGame SRCALPHA flag, which provides per-pixel alpha for the surface which is being drawn or blitted to the screen. In theory this is fine and gives better results, but due to the lack of hardware acceleration support in PyGame, this becomes incredibly intensive on the CPU thread and decreases performance. In order to alleviate this, surface-level alpha should be used for all transparency effects instead.