FEAT add auto mps support

[paulasquin]

• Add MPS support with auto DEVICE selection between cuda, mps and cpu
• Applied PEP refacto to the 3 modified files (single quotes, lines max length etc)

Happy to make Apple's ferret work in my Macbook, even if that's a bit slow.

Tested with ferret-13b-v1-3, Macbook M3 Max 14" GPU 40 Core, 64Go RAM, using

export PYTORCH_MPS_HIGH_WATERMARK_RATIO=0.0 # to disable upper limit for memory allocations

featuring my own photo, thank you ferret, even if I don't see much birds.

[paulasquin]

Thanks @gucxa2-mYjnyb-wyjvyg

@Haotian-Zhang if this looks interesting to merge for you, or you'd need any modification, please let me know