Add @transient to large fields and use NativePartition to reduce serialization overhead

[Deegue]

Is your feature request related to a problem? Please describe.
Mark large non-serializable fields with @transient annotation across NativeExec classes to reduce task serialization size and memory usage.

Describe the solution you'd like
Introduce NativePartition[P] wrapper to carry original partition payloads through NativeRDD without re-indexing into the partitions array at execution time, which avoids serializing the full partitions array.

Describe alternatives you've considered

Additional context