support for better quality terminal graphics formats

for example, Sixels, Kitty, iTerm2, Unicode mosaics...

chafa https://hpjansson.org/chafa/ can handle generating these from normal images and has python bindings https://chafapy.mage.black/

talk about adding image support in textual: https://github.com/Textualize/textual/discussions/1191?sort=old