Add support for custom Vision model

[leslielazzarino]

Description:

Added support for vison models in the advanced mode (previously "Advanced Chat") of the chat settings.
Related Issue:

#162

Changes Made:

• renamed the "Advanced Chat" mode to "Advanced"
• added an optional filed in the "Add Model" modal to add the mmproj model
• changed settings, so that models with an mmproj model available are recognized as vision models

Testing Done:

Tested locally with Nvidia GPU and CPU.

Screenshots:

Checklist:

• I have tested the changes locally.
• I have self-reviewed the code changes.
• I have updated the documentation, if necessary.