[Feature Request]: drag and drop

### 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 ?

ability to drag and drop in and out of subgraphs while maintaining existing links or shift click node + subgraph and right click for menu option "add to subgraph". the reverse would also be nice

### Proposed workflow

create subgraph
click and hold outside node
drag onto subgraph

or

select multiple nodes + subgraph
right click subgraph
"add nodes to subgraph"

### Additional information

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-4476-Feature-Request-drag-and-drop-2356d73d365081f89a6fd02f10dc2253) by [Unito](https://www.unito.io)