partition_queries: maintenance / simplification of code (also in the old vis_io)

[FedeMPouzols]

After the addition of the more generic and more up-to-date function create_partition() it should be possible to simplify and remove stuff in partition_queries that is either deprecated or very unlikely to be used in the future. This includes make_partition_ids_by_... functions.

[FedeMPouzols]

I think that this branch has now an acceptable first step in removing outdated stuff from partition_queries and related files.

• Removes several functions from partition_queries (170+ lines), and the tests and other code left dangling after that.
• Also removes vis_io for good.
• Also removes an unused file (ms_column_descriptions_dicts) which I think has been there since the beginnings of cngi-io
• In the vis_tutorial notebook, the text is re-synced with recent changes from PR #201.

We can still remove a couple of more functions from partition_queries, but there is an open question before going ahead, and also I'd favor a more incremental approach, as removing these implies a cascade of removals that has terrible effects on the current unit tests, not only of old stuff but also of very alive stuff under _ms and _ms/_tables. This further removal of old partition functions would be less traumatic once we get to the stage that we can add equivalent/counterpart unit tests for the conversion.py functions, and as those grow then we could more smoothly remove the remaining old tests and functions from partition_queries.

[FedeMPouzols]

There are old functions in partition_queries that filter the intents that seem adequate for an SPW (intents with 'WVR' are removed if the SPWs have names that are not related to WVR subscans, and viceversa, only keep the WVR intents if the SPW name indicates it is a WVR subscan). I think this is not currently included in the new create_partitions() function.