Introduce a Timeout for FHIR Search Requests

[alexanderkiel]

In case the FHIR server is slow to respond, it would be good to have a configurable timeout in order to fail fast and free resources. The timeout will apply on single page basis and not for the whole FHIR search request chain.

The env var should be called FLARE_FHIR_REQUEST_TIMEOUT. The default should be 30 seconds.

[KutSaleh]

Is this implemented, yet?

I'm asking because I'm suddenly getting timout errors from flare matching the suggested 30 secconds. But my FHIR server has a much higher read idle timeout configured. The error message is

{
    "error": "connection timed out after 30000 ms: my.fhir.server.de/123.123.123.123:443"
}