change(blit): Allow to blit images with alpha channel

bootloader/bootloader-display.c

epicardium/epicardium.h

epicardium/main.c

epicardium/modules/display.c

epicardium/modules/panic.c

hw-tests/dual-core/main.c

hw-tests/hello-world/main.c

hw-tests/ips/main.c

lib/gfx/framebuffer.c

lib/gfx/framebuffer.h

lib/gfx/gfx.c

lib/gfx/gfx.h

pycardium/modules/py/display.py

pycardium/modules/sys_display.c