Move standard icons to Beamracer's RAM

[Maciej Witkowiak]

Having OK, CANCEL, DISK, etc. icons stored inside Beamracer RAM will free some memory.

Check what needs fewer bytes:

• keep space of longest icon and copy data from BR RAM there and unpack that buffer
• unpack directly from BR RAM into BR RAM
• since we need special code path for standard icons anyway they can be all kept unpacked in BR ram and copied using fastest port to port transfer