Main Changes

• ReadResponse<T> now accepts an IModbusMessage request parameter. This allows the response handler to access the original request's slave address and function code, enabling more flexible and accurate response parsing, especially for broadcast scenarios.
• The methods ValidateResponse and ShouldRetryResponse are now marked as virtual. This allows subclasses to override them and implement custom logic (such as not enforcing slave ID match when the request is a broadcast).

Why

• Broadcast requests (slaveId = 0) require special handling, since any slave (1-247) can reply and strict address checks should be relaxed.
• Making validation and retry logic virtual makes it much easier for downstream users to customize behavior for different Modbus RTU devices or edge cases without modifying the base library.

Additional Notes

• These changes are backwards compatible except for the new parameter in ReadResponse<T>.
• Improves robustness and flexibility in noisy or complex Modbus RTU environments.