Immediate Dead letter option

### Describe the feature

A way of failing and immediately putting message to configured deadletter queue

### Use Case

if in handler code we are able to work out that no amount of retrying will resolve the issue without intervention there is no point wasting the processing retrying the message.

### Proposed Solution

some syntactic sugar such as ` return MessageProcessStatus.ImmediatelyDeadletter();`

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### AWS.Messaging (or related) package versions

AWS.Messaging 0.9.2

### Targeted .NET Platform

net8.0

### Operating System and version

AmazonLinux

Start by tracing the message handler flow, retry behavior, and configured dead-letter queue around the proposed MessageProcessStatus.ImmediatelyDeadletter() result. Clarify how this status should differ from ordinary failures and define done as immediate placement of the message on the configured dead-letter queue without further retries.

Written by the indexing model from the issue text.