Easier models.csv setup

[Kilvoctu]

This PR aims to make setting up the models.csv a little more easy

Currently a line in the csv file needs the full model name for the 2nd value. Something like this

display_name|model_full_name|activator_token    
SD 1.5|sd-v1-5-pruned-emaonly.ckpt [81761151]|

When downloading a new model and adding it to the csv, it's a little tedious because there's not a quick and easy way to know the short hash. I'd like to be able to only enter its name, like this

display_name|model_full_name|activator_token
SD 1.5|sd-v1-5-pruned-emaonly|

Some concerns:

• It doesn't know the file extension. So if someone has "model.ckpt" and "model.safetensors", aiya will select "model.ckpt".
• I really don't want to break all the existing models.csv that people may have. I need to find a way for both the normal way and this new way to work simultaneously.
• I've got to make sure that the 📋 button still provides all the information correctly like before.
• Models nested within folders need to be supported as well.
• Probably other things I can't think of at the moment.

At some point, I'd like a better way to edit the models.csv than manually opening it up and entering fields, but I can't think of anything simple and practical.

[Kilvoctu]

Tested on a mixed models.csv (some full names, some short names, nested and non-nested), with many prompts. Tested buttons.
Models swapped properly each time, no other bugs that I can see..