[FEAT] Cubeviz: Get glue-astronomy translators to work with latest Spectrum1D and/or NDCube

[javerbukh]

Description

Get glue-astronomy translators to work with latest Spectrum1D and/or NDCube.

Related to PR #547

Additional context

[rosteen]

Note that I did some work already in glue-astronomy to update the Spectrum1D translator, but @orifox found that the current iteration only works if a full WCS has been specified for the Spectrum1D, not if you instantiate the Spectrum1D by giving it only a spectral_axis. There are (at least) two problems due to the fact that in this case, Spectrum1D creates a SpectralGWCS lookup table based on the spectral_axis on initialization:

1. The glue-astronomy translator currently uses wcs.swap_axes, which doesn't exist for a GWCS.
2. If the above is remedied (I tried adding an isinstance check), glue core then throws an error where it looks for axis names in the Data object coords, and fails on an IndexError because it's looking for three axis names and there is only one axis in the GWCS.

EDIT: It's unclear to me if this is somehow caused by needing to convert into a SpectralCube and would thus be resolved by #547. Fingers crossed.

[rosteen]

Looks like this should have been closed a while ago.