spearmint: Move be_ai_chat.c to Game VM

be_ai_chat.c doesn't need to be in the engine so move it to the Game VM.
Increase qvm hunk size size to handle loading the chat data.
spearmint: Remove stuff from botlib.h only needed in Game VM
spearmint: Remove cgame screen/font sizes from q_shared.h
spearmint: Fix scaleable font DPI in narrow windows