eventhubs: Can we combine try_add_event_data() and try_add_amqp_message()?

[richardpark-msft]

Today, there are two methods to add an event, but for different types:

let ed = EventData::from("Hello");
let ed2 = EventData::from("Hello");

let added1 = batch.try_add_event_data(ed, None)?;

if !added1 {
    panic!("well, dang")
}

let added2 = batch.try_add_amqp_message(ed2, None)?;

if !added2 {
    panic!("well, dang")
}

It looks like I can pass EventData to both the AMQP and Event Data specific functions, so merging these into a single function would simplify the API surface, while not compromising on functionality.