[FEATURE REQ] Support customizing the EventHubsProducerFactory and EventHubsProcessorFactory

**Is your feature request related to a problem? Please describe.**
The same customization of Service Bus is also necessary for Event Hubs, see more from [AzureServiceBusMessagingAutoConfiguration](https://github.com/Azure/azure-sdk-for-java/pull/42486/files#diff-1d4cc0e6b2e60f97bc9f58cc00a2c16b8294ac83a766c874f1b444736b494792).

**Describe the solution you'd like**
Support the customizer, token according to `DefaultEventHubsNamespaceProcessorFactory` and `DefaultEventHubsNamespaceProducerFactory`.

**Describe alternatives you've considered**
N/A

**Additional context**
Similar scenario may be covered, see from https://github.com/Azure/azure-sdk-for-java/issues/44414

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