Add EncodedStringVectorBatch to expose string dictionary in VectorBatch

Propose to add EncodedStringVectorBatch to expose string dictionary in VectorBatch. Exposing string dictionary will benefits as bellow:

• Enable computation over encoded data. By exposing dictionary in vector batch we would be able to implement filter operator in a more efficient way. In our POC, by enabling encoded data based filter, we achieved 8% E2E perf improvement on tpch q1
• Make data serialization more efficient. Currently when serializing Orc Vectorbatch, we have to copy all the strings in a vector even though the string data is already dictionary encoded. Exposing String Dictionary will enable vector batch serializer to remove unnecessary string memcpy, which will greatly improve serialization efficiency.