Pass request to filter factories

Currently, we pass a simple dictionary to the `filter_builder`:

https://github.com/developmentseed/stac-auth-proxy/blob/0ba2237f8a0d6c9574db899ee050224d5a3b3b0c/src/stac_auth_proxy/middleware/Cql2BuildFilterMiddleware.py#L79-L90

We should ensure that the request itself is exposed to the filter factory, enabling access to any available property within that request (such as DB connections that are available on the `request.app`).