Allow Project search API endpoint to count `total_results` higher than 10,000

Feature Requests
2

Mentioning @pleary since they responded to a previous related report:

https://forum.inaturalist.org/t/v1-taxa-endpoints-cap-observations-count-at-10-000/7373

There’s another related request:

https://forum.inaturalist.org/t/allow-taxon-search-api-endpoint-to-count-total-results-higher-than-10-000/9327

And a Bug Report made for this same issue that was turned into this request:

https://forum.inaturalist.org/t/allow-project-search-api-endpoint-to-count-total-results-higher-than-10-000/81436