Browse search for series is very very slow

Found in PINES. Original report from staff: "Series search in browse search silently fails. No titles are retrieved in either the staff client or public OPAC. Other browse searches do retrieve records."

Tracking down the actual DB query in the logs shows that the query takes 164 seconds: 2020-11-23 15:51:19 db01 postgres[114948]: [483-1] 2020-11-23 15:51:19.960 EST [114948] evergreen@evergreen LOG: duration: 164826.245 ms statement: SELECT * FROM metabib.browse( 'series', 'agatha raisin', '1', NULL, 'f', NULL, '20' ) AS "metabib.browse" ;

I've investigated local optimization options, but nothing is sticking out. Perhaps we need more/better indexing somewhere.

Evergreen 3.6 to current master
OpenSRF 3.2.1
PostgreSQL 9.6/10
Ubuntu 18.04