Extract a spectra under a position (HiPS3D related)

[bmatthieu3]

What would be great is, once ipyaladin will use Aladin Lite >= 3.7, to provide a method that extracts a full spectra at a (lon, lat) position using a HiPS3D survey. Maybe by default the center of view could be considered.
Output of that extraction could be:

• a https://docs.astropy.org/en/latest/api/astropy.coordinates.SpectralCoord.html experimental astropy native type
• a numpy 1d array + astropy.wcs
• a specutils type https://specutils.readthedocs.io/en/stable/

but I am welcome to other possible outputs as I did not look a lot at it.