add parquet counters for benchmark

1. add getCounters in ContextUtil for hadoop versions comapatibility
2. add counters for TotalBytes, TotalRead, TimeRead during reading parquet files. It can be turned off by setting flags(parquet.benchmark.bytes.read, parquet.benchmark.bytes.total, parquet.benchmark.time.read) to false
3. add unit tests for counters
4. refactor TestInputOutputFormat so adding new tests is easier