[SPARK-4573] [SQL] Add SettableStructObjectInspector support in "wrap" function

Hive UDAF may create an customized object constructed by SettableStructObjectInspector, this is critical when integrate Hive UDAF with the refactor-ed UDAF interface.

Performance issue in `wrap/unwrap` since more match cases added, will do it in another PR.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #3429 from chenghao-intel/settable_oi and squashes the following commits:

9f0aff3 [Cheng Hao] update code style issues as feedbacks
2b0561d [Cheng Hao] Add more scala doc
f5a40e8 [Cheng Hao] add scala doc
2977e9b [Cheng Hao] remove the timezone setting for test suite
3ed284c [Cheng Hao] fix the date type comparison
f1b6749 [Cheng Hao] Update the comment
932940d [Cheng Hao] Add more unit test
72e4332 [Cheng Hao] Add settable StructObjectInspector support