[Fix] fix the position of row and col embedding

[Leaveson]

Description

This PR addresses an issue in the MatNet implementation where the positions of the row embedding and column embedding were swapped.

Motivation and Context

It is a significant model for handling matrices in NCO For more details, please refer to the (original paper)

Types of changes

What types of changes does your code introduce? Remove all that do not apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds core functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Example (update in the folder of examples)

Checklist

Go over all the following points, and put an x in all the boxes that apply.
If you are unsure about any of these, don't hesitate to ask. We are here to help!

• My change requires a change to the documentation.
• I have updated the tests accordingly (required for a bug fix or a new feature).
• I have updated the documentation accordingly.

[fedebotu]

Thanks for the XMas eve commit 🎄
We discussed today with @Leaveson, and it seems good to go!
Tagging @LTluttmann for a double check before merging since it seems we did not notice this in scheduling problems - perhaps due to the fact that the direction of row/col did not matter in those cases 👀