Global variables for model, CLIP, VAE for more organized and fast workflows

### Feature Idea

Currently every Ksampler and node requires to connect Model, CLIP, VAE, positive, negative manually to each node. Partially problem of having too many lines could be “solved” by rerouting lines.

Wouldn’t it be easier for user if by default each new node would reference some sort of global variables with model, VAE, CLIP, and Conditioning, with an ability to override it when another link is connected to the input socket?
There’s a Set/Get node in third party pack, but it only works with existing limitations
https://github.com/kijai/ComfyUI-KJNodes

### Existing Solutions

_No response_

### Other

_No response_