Refactor convertBroadcastExchangeExec to use direct type parameter instead of pattern matching #1423
Description
Description:
This PR refactors convertBroadcastExchangeExec to use a more concise and type-safe definition.
The previous implementation used pattern matching on SparkPlan, which is unnecessary since the function is always invoked with a BroadcastExchangeExec instance.
The new version improves readability, aligns with other similar conversion methods, and removes redundant code.