AMQP_1 Output: No Support for AMQP Message Properties (e.g., group-id for Azure Service Bus SessionId)

The amqp_1 output currently supports:

• AMQP ApplicationProperties (application_properties_map)
• AMQP MessageAnnotations (meta)

…but it does not support the AMQP Properties section (AMQP 1.0 §3.2.4), which includes:

• group-id (required for Azure Service Bus SessionId)
• message-id
• subject
• correlation-id
• etc.

Possibly relevant file:

internal/impl/amqp1/output.go
Specifically the Write() method that constructs the AMQP message.

Values set via meta always become MessageAnnotations:
m.Annotations[k] = v

All values assigned via application_properties_map become ApplicationProperties:
m.ApplicationProperties = applicationProperties

There is no code populating the AMQP Properties frame:
m.Properties = &amqp.MessageProperties{ ... }
..except for optional To.

Because of this, it's currently impossible to set: Properties.group-id = "<SessionId>"
which Azure Service Bus requires for session-enabled queues or topics. Messages without this field are rejected with:
The SessionId was not set on the message

Requested Feature: Support for setting AMQP Message Properties, for example:

amqp_properties:
  group-id: "session-123"
  message-id: "my-id"
  subject: "event"

or allow them through meta:
meta "amqp_properties.group-id" = "session-123"

This would make the AMQP_1 output fully AMQP-compliant and enable interoperability with Azure Service Bus and other brokers requiring AMQP Properties.

Thanks
It would be awesome to have support for this - it makes the AMQP_1 output a lot more flexible.

Start in internal/impl/amqp1/output.go, focusing on Write() and the existing AMQP message construction, including the optional To property. Review how application_properties_map and meta are mapped, then determine how the requested AMQP Properties values should enter the configuration. Done means group-id and the other requested properties can be set on outgoing messages for brokers such as Azure Service Bus.