[ENG-8221][ENG-8038] less database data; part 1

[aaxelb]

first step of a less reckless approach to #876 -- mirror RawDatum.expiration_date to IndexcardRdf.expiration_date in preparation for dropping RawDatum (and before eventually renaming IndexcardRdf to ResourceDescription)

• add expiration_date field to abstract IndexcardRdf model (base for ArchivedIndexcardRdf, LatestIndexcardRdf, SupplementaryIndexcardRdf)
• when ingesting, save expiration_date in those tables as well as RawDatum
• add trove management command migrate_rawdatum_expiration to copy existing expiration_date from RawDatum to SupplementaryIndexcardRdf (the only kind that expires, in current production usage)

ENG-8221

[coveralls]

coverage: 81.24% (-0.004%) from 81.244%
when pulling 08d4804 on aaxelb:feature/eng-8038--migrate-expirations
into 4a73dfe on CenterForOpenScience:develop.

[mfraezz]

One minor note, otherwise LGTM. Benchmarking indicated that this may take a while, but a manageable amount of time.

[mfraezz]

Rewrote this loop slightly to be non-modifying, and did some benchmarking. A little slow to start due to _raw_qs and the size of the RawDatum table, but appears workable. EXPLAINALYZE'd the slowest query, and no apparent way to speed it up:

                                                                                QUERY PLAN

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Index Scan using share_rawdatum_expiration_idx on share_rawdatum  (cost=0.57..42489486.91 rows=3096 width=1069) (actual time=0.284..13910.434 rows=483200 loops=1)
   Index Cond: (expiration_date > '2025-06-16'::date)
   Filter: (id = (SubPlan 2))
   Rows Removed by Filter: 172539
   SubPlan 1
     ->  Limit  (cost=67.95..67.95 rows=1 width=12) (actual time=0.006..0.006 rows=1 loops=483200)
           ->  Sort  (cost=67.95..68.20 rows=102 width=12) (actual time=0.005..0.005 rows=1 loops=483200)
                 Sort Key: (COALESCE(u0.datestamp, u0.date_created)) DESC NULLS LAST
                 Sort Method: quicksort  Memory: 25kB
                 ->  Index Scan using share_rawdatum_01248af3 on share_rawdatum u0  (cost=0.57..67.44 rows=102 width=12) (actual time=0.002..0.004 rows=4 loops=483200)
                       Index Cond: (suid_id = share_rawdatum.suid_id)
   SubPlan 2
     ->  Limit  (cost=67.95..67.95 rows=1 width=12) (actual time=0.014..0.014 rows=1 loops=655739)
           ->  Sort  (cost=67.95..68.20 rows=102 width=12) (actual time=0.014..0.014 rows=1 loops=655739)
                 Sort Key: (COALESCE(u0_1.datestamp, u0_1.date_created)) DESC NULLS LAST
                 Sort Method: quicksort  Memory: 25kB
                 ->  Index Scan using share_rawdatum_01248af3 on share_rawdatum u0_1  (cost=0.57..67.44 rows=102 width=12) (actual time=0.005..0.012 rows=5 loops=655739)
                       Index Cond: (suid_id = share_rawdatum.suid_id)
 Planning time: 6.497 ms
 Execution time: 13939.482 ms
(20 rows)