[Implement] "Cache Sprite" Packet

[acagliano]

This packet needs the following format:

 struct {
                uint8_t control_code;
                uint8_t type;
                uint8_t slot;
                uint24_t size;
                gfx_sprite_t sprite;
            } *packet = (void*)data;

Type is ether 0 for terrain or 1 for player.
Slot is the Type ID of the terrain or PlayerID of the player.
Size is the decompressed size of the sprite.
If the serial buffer on calc needs to be larger to accomodate, lmk.