[SPARK-3720][SQL]initial support ORC  in spark sql

Provide a initial support for orc file formate in spark sql,  support for both reading and writing ORC files . user can use ORC file just like parquet as follow:
```
... ...
  rdd.registerTempTable("records")
  rdd.saveAsOrcFile("pair.orc")
  val orcFile = sqlContext.orcFile("pair.orc")
  orcFile.registerTempTable("orcFile")
  sql("SELECT * FROM orcFile").collect().foreach(println)
```

Why convert all nulls to empty strings?