Fixes#2353
Adds a new endpoint to list pages in a collection, with filtering
available on `url` (exact match), `ts`, `urlPrefix`, `isSeed`, and
`depth`, as well as accompanying tests. Additional sort options have
been added as well.
These same filters and sort options have also been added to the crawl
pages endpoint.
Also fixes an issue where `isSeed` wasn't being set in the database when
false but only added on serialization, which was preventing filtering
from working as expected.
98a45b0d85