Reordering of inputs and outputs

### Feature Idea

We need the capability to reorder input and output nodes!! Please, with sugar on top...

When working with large subgraphs, with a lot of inputs and outputs, it's currently impossible to reorder them and also not possible to insert new inputs and outputs in-between. Which makes it ultra cumbersome to work with subgraphs in general. I consider this a show stopper.

Hope you can find a solution to this.

Thanks!

### Existing Solutions

_No response_

### Other

_No response_

No file, test, or entry point is named in the issue. Start by locating the graph and subgraph handling for input and output nodes, then determine how their order is represented and edited. Done should include reordering existing inputs and outputs and inserting new ones between them, with behavior verified for large subgraphs.

Written by the indexing model from the issue text.