Support uploading images for vision-capable models

[blacktemplar]

The current UI allows only text-based requests for all models. The newest models like gpt-4-turbo support also vision.

This is a feature request to be able to upload an image inside a conversation with vision-capable models.

[github-actions]

This issue is stale because it has been open for 10 days with no activity.

[github-actions]

This issue was closed because it has been inactive for 2 days since being marked as stale.