Add script to update processing table column layout

[akremin]

This adds a command line script, desi_reformat_proctables, to update the processing table column layout. As of now, there have only been two versions of the processing tables. The old tables used CAMWORD instead of PROCCAMWORD used in the modern processing tables to represent the cameras used in the processing. The old tables also lack BADAMPS, LASTSTEP, and EXPFLAG.

The script takes a list of nights, range of nights, or "all" to run on all processing tables.

For each identified table, the script will rename CAMWORD to PROCCAMWORD if found. If BADAMPS, LASTSTEP, EXPFLAG, or any other column defined in desispec.workflow.proctable.get_processing_table_column_defs() is missing, the code will add the column where the value of each row is the default for that column type. If other columns are found in the existing table that aren't in the list of current columns given in desispec.workflow.proctable.get_processing_table_column_defs(), the column is removed.

Tests

I ran this at NERSC on a copy of the daily processing tables. The processing tables and a notebook verifying that the output files have all the expected columns can be found here:
/global/cfs/cdirs/desi/users/kremin/PRs/modernize_proctables/daily/

The old files that are replaced have a *.replaced-{TIMESTAMP}.* added to the file name. The new files have the expected name for a processing table of a specprod on a given night.

[coveralls]

coverage: 30.091% (-0.07%) from 30.164%
when pulling 43cd53f on modernize_proctables
into 97b1748 on main.

[sbailey]

I put some cosmetic requests inline.

From desihub/desisurveyops#209, I thought that night 20210328 was one of the nights that needed to be updated, but when I tried to run a test on that night it says:

[login30 daily] desi_reformat_processing_tables --dry-run -n 20210328
Nights:  [20210328]
INFO:tableio.py:323:load_table: Found table: /global/cfs/cdirs/desi/users/sjbailey/spectro/redux/daily/processing_tables/processing_table_daily-20210328.csv
/global/cfs/cdirs/desi/users/sjbailey/spectro/redux/daily/processing_tables/processing_table_daily-20210328.csv has all of the expected columns, not updating this table.
Exposure table regenerations complete

Please check and/or post example nights that do need to be updated.

For the record: normally I'd be itching to ask for unit tests, but since I expect this to be a one-off script to update some tables and then be done with it, that seems less critical.

[akremin]

I have made all of the requested changes. Unfortunately, now there is an issue with a docstring somewhere. I will resolve that tomorrow morning.

All nights on or before 20210208 require this reformatting. I will also investigate whether 20210328 needs reformatting that this is missing.

I also failed to mention that I ran tests at nersc on a copy of the daily processing tables. The processing tables and a notebook verifying that the output files have all the expected columns can be found here:
/global/cfs/cdirs/desi/users/kremin/PRs/modernize_proctables/daily/

The old files that are replaced have a *.replaced-{TIMESTAMP}.* added to the file name. The new files have the expected name for a processing table of a specprod on a given night.

[akremin]

@sbailey I have fixed the docstring issue. I also double-checked why 20210328 did not need updating. The crash on that night is unrelated to the processing tables format. The issue for that night is in updating results from the queue. The solution for 20210328 might require a further code change, but I'd like #2351 and #2376 merged first if you're happy with both. That way we can get all of the tables in the same format and I can adapt the queue-checking code off of #2351 which also modifies that code.