Remove wildcard queries from solr [MJ-979]

This removes the \*domain.jobs\* queries that we were using by instead querying on SavedSearch_company_id (which was added to solr during today's deployment). Queries on exact domain will still use the \*domain.jobs\* syntax for now, but those are going to happen far less often and be not nearly as expensive.

Fixed in this pull request but not directly related to the ticket: I noticed we could do prefix faceting a little bit better, so I went ahead and added that to this pull request as well.

All tests pass.