Python Bindings, optionally pass PIL image

[msharp9]

Would love if the load_preprocess_encode_image python binding allowed me to pass in a PIL image instead of just a file path. In workloads where you already have an image in memory, it's a huge hit to latency to have to save the image to disk just so it can be passed into a clip_cpp model. Anytime we can avoid disk reads/writes is a benefit.

(Note it doesn't have to be a PIL Image, but that's what I have.)