[FEATURE REQ] Allow users to customize SSLContext in azure-core-amqp and eventhubs

[ChrisCollinsIBM]

As requested in #17963 and #17907 we still face this issue today where we can't pass a preferred SSLContext into the EventHubClientBuilder to cascade into where the ConnectionHandler.java creates the SSLContext.

Individual client connections in a large shared JVM shouldn't rely on the SSLContext.getDefault() to cover all use cases and should be configurable on a per-client basis. Ideally this would be exposed in the already very expansive EventProcessorClientBuilder

This is very common in client SDKs to expose (Apache HTTPClient, etc).

Can we get this re-looked at?