Add an example showing how to use the AIA datacubes that are aligned with the IRIS FOV

[wtbarnes]

LMSAL provides AIA datacubes that are aligned with the IRIS FOV for various IRIS observations. We should provide an example gallery entry that shows how to work with these datacubes, probably using NDCube. This could include how to download them, how to parse them, how to fix any metdata as needed, how to plot them and how to slice them with NDCube.

This very old notebook shows how to do this with one particular cube, though it uses a much older version of ndcube and sunpy so it certainly needs updating.