Tweak solr cache configs

We currently have two caches that have very high hit rates, the `filterCache` and the `perSegFilter` cache

`filterCache` is I believe used whenever with use the `fq` parameter. We use this a lot of things like filtered author queries, reading log queries, etc.

`perSegFilter` is apparently "custom cache currently used by block join". I believe we use block join indirectly for our edition-aware queries, which power huge chunks of the site.

Increasing the sizes of these caches might improve solr performance.

### Stakeholders

@scottbarnes @tfmorris

Start by locating the Solr configuration entries for the filterCache and perSegFilter caches, then review the linked cache hit-rate evidence and their current sizes. Compare potential size increases against observed Solr performance and define completion as a validated configuration change that improves performance without unacceptable resource use.

Written by the indexing model from the issue text.