Create a default ApacheHttpPoster to replace the current OkHttpPoster

[jasonjkeller]

We occasionally get reports from customers that are having trouble reporting JFR data while Java agent data seems to report just fine. The Java agent uses an Apache HTTP client while JFR poster uses OkHttp. It's unclear if the OkHttp client is at fault in these scenarios, but it would be ideal to align the Java agent and JFR to use the same Apache HTTP client so that we can rule out any discrepancies in the future.

In addition to that, there have been other known issues with the OkHttp client that would be resolved by migrating to Apache, such as the lack of support for HTTPS proxies and dependency clashes due to transitive Kotlin dependencies brought in by OkHttp.
newrelic/newrelic-telemetry-sdk-java#325

Any new HTTP client must be compatible with Java 8+.

[workato-integration]

https://new-relic.atlassian.net/browse/NR-335340