[IS-44/feat]: add context to consumer message handler

[l4mby]

This pr adds a DeliveryContext to the consumer message handler.
Through this context it is possible to accept, discard or requeue a message, for example:

const consumer = await connection.createConsumer({
      queue: { name: "test-queue" },
      messageHandler: (context, message) => {
        context.accept()
        // or ...
        context.discard()
        // or ...
        context.requeue()
      },
})