Add optional additional_query_params config to provider DAGs

[stacimc]

Problem

It would be nice to add a conf option to the provider DAGs called additional_query_params, which would be merged with the results of get_next_query_params for each batch.

Description

An example use case for this option would be to run a provider DAG but restrict the search to a single user by adding a user_id query param to all requests.

Additional context

This would be handy, for instance, when backfilling records for a single user, as we wanted to do in #3490.