Description

Add --disable-batch-request-retry flag to rpcconsumer and rpcsmartrouter
that prevents JSON-RPC batch requests from being retried.

Changes:
- Add IsBatch() method to ChainMessage interface for clean batch detection
- Implement batch detection via type assertion on JsonrpcBatchMessage
- Check flag in retryCondition() of both consumer and smartrouter state machines
- Add defense-in-depth check in RelayProcessor.shouldRetryRelay()
- Add comprehensive tests for the new flag behavior

The flag is enabled by default (batch retries disabled), users can enable
retries with --disable-batch-request-retry=false if needed.

Closes: #XXXX

Author Checklist

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please add links to any relevant follow up issues.

I have...

• read the contribution guide
• included the correct type prefix in the PR title, you can find examples of the prefixes below:
• confirmed ! in the type prefix if API or client breaking change
• targeted the main branch
• provided a link to the relevant issue or specification
• reviewed "Files changed" and left comments if necessary
• included the necessary unit and integration tests
• updated the relevant documentation or specification, including comments for documenting Go code
• confirmed all CI checks have passed

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your handle next to the items reviewed if you only reviewed selected items.

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• confirmed the correct type prefix in the PR title
• confirmed all author checklist items have been addressed
• reviewed state machine logic, API design and naming, documentation is accurate, tests and test coverage