[ENG-6708][ENG-7286] improved trovesearch_denorm...

[aaxelb]

improvements to trovesearch_denorm index strategy:

• skip indexing nested "identifier" text (saves 107 fields)
• allow wild-card properties only to depth 1 (disallow cardSearchText[*.*])
• reduce number_of_replicas from 2 to 1
• fix: backfilling a new index shouldn't clear earlier indexes

other:

• use select_related to avoid n+1 queries on n search results
• stop hashing so much rendering valuesearch responses (get unique ids other ways)

[coveralls]

coverage: 91.765% (+0.02%) from 91.742%
when pulling 9ae8ba9 on aaxelb:fix/denorm-optimiz
into 86d1d56 on CenterForOpenScience:develop.

[felliott]

LGTM!