Support for first-acquirer field

[Havret]

Feature description

Extend Message API with first-acquirer field. If the value is true, then this message has not been acquired by any other link (see section 3.3). If the value is false, then this message MAY have previously been acquired by another link or links.

Feature in action

var msg = await _consumer.ReceiveAsync(_cts.Token);
if (msg.FirstAcquirer)
{
    // this message has not been acquired by any other link
}
else
{
    // this message MAY have previously been acquired by another link or links
}

Additional context

OASIS Advanced Message Queuing Protocol(AMQP) Version 1.0 - section 3.2.1