develop
Fixed #4564 - Batch Consumers no longer use the MessageId for ordering, instead opting to use the sent time, transport sent time, or the receipt time.
Added nullable to SQS transport to hopefully catch any further issues with null return types (though I don't think the SDK uses it)
Integration of all external packages into MassTransit, split out into Abstractions, Middleware, and the core MassTransit assembly.
Adding nullability to abstractions, and fixing warnings
Replace Array.Empty with collection expression
Client Request Handle change to start time when request is actually sent, to avoid delays in middleware processing affecting timeout
Massive file cleanup