[Feature Request]: Bring to Front / Send to back (node z-ordering)

### Is there an existing issue for this?

- [x] I have searched the existing issues and checked the recent builds/commits

### What would your feature do ?

I'd love to be able to control the Z-ordering of nodes.

In my own local workflows, I often move multiple processing nodes behind a note node, just for cleanliness. When I want to edit one, I have to move the note out of the way and move it back.

Being able to select "send to back" would make for easy access the nodes underneath, while "bring to front" would restore the "cover" note.

### Proposed workflow

1. Right click a node
2. Select "Bring to front" or "Send to back"
3. Z-order changes

### Additional information

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-4317-Feature-Request-Bring-to-Front-Send-to-back-node-z-ordering-2236d73d36508162b753c5025ab264f1) by [Unito](https://www.unito.io)