Previously the color of a link would simply use the type of the target
slot and fallback to the type of the origin slot. When a connection is
made to a node that accepts the any type ('*'), the link has the green
color of an unknown type.
Instead, when a connection is made, the type of a link is now calculated
as the greatest common type of the source and destination. This means
that connections to reroutes are correctly colored.
| Before | After |
| ------ | ----- |
| <img width="360" alt="before"
src="https://github.com/user-attachments/assets/a5544730-e69a-4c85-af33-b303bb30ae71"
/>| <img width="360" alt="after"
src="https://github.com/user-attachments/assets/7d7b59fd-1b79-440b-a97d-a1657313c484"
/>|
The code for calculating common types already exists, it has simply been
moved into litegraph and given a more descriptive name.
Resolves#7196
┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7211-Color-links-as-common-type-2c16d73d365081188460f6b5973db962)
by [Unito](https://www.unito.io)
---------
Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
