Allow for more aggressive caching than the full URL.

Ability to leave off all searchParams from a URL. This will allow for much better cache hits.

Ideal scenario is to (also?) have a whitelist of searchParams that we keep.

Start by locating the code that derives cache keys from request URLs and any tests covering searchParams. Confirm whether the default should drop all parameters and how a whitelist is configured; done means equivalent URLs share a cache key while whitelisted parameters remain distinct.

Written by the indexing model from the issue text.