Easy access to visibility data within the Karabo framework

[chrisfinlay]

Currently, to the best of my knowledge, the Visibility object is simply a wrapper to the generated MS file path. Currently installed packages (casacore) allow one to access the data stored in the MS file but this has no Karabo wrapper to make it easy for the user.

I proposed to include at the very least dask-ms as a new dependency as it gives easy access to the data inside MS files and ideally xaaray-ms or xradio which make the data even easier to understand for the user.

All of these proposed libraries present the MS file contents to the user in the form of an xarray dataset/datatree object which is both self describing and lazy loaded.

[d3v-null]

There's already a dependency in Karabo, pyuvdata that can read measurement sets

here's an example of measurement set visibility access

https://pyuvdata.readthedocs.io/en/latest/uvdata_tutorial.html

I added this pretty recently