[SPARK-17654] [SQL] Propagate bucketing information for Hive tables to / from Catalog

[tejasapatil]

What changes were proposed in this pull request?

Currently Spark does not respect bucketing for Hive tables. This PR includes following changes:

• will extract table's bucketing information in HiveClientImpl
• while writing table info to metastore, MetastoreRelation now populates the bucketing information in the hive Table object
• HiveTableScanExec now exposes outputPartitioning and outputOrdering as per bucketing spec.
• InsertIntoHiveTable now exposes requiredChildDistribution and requiredChildOrdering based on the target table's bucketing spec.

TODOs (which will be done in linked PRs and not this one):

• ClusteredDistribution does not guarantee the number of partitions (which corresponds to output bucket files created) generated. This will require adding strict guarantees to ClusteredDistribution. I think it will need more thought and better to do incrementally and not packing in this PR.
• While writing to bucketed files, Hive's hashing function should be used. I have a PR open to implement Hive hashing native in Spark : [SPARK-17495] [SQL] Add Hash capability semantically equivalent to Hive's #15047
• Allow creating Hive bucketed tables

How was this patch tested?

Tested with Hive tables created locally. Adding a new test case will need implementing bucketed table creation which is not supported :( Suggestions welcome.

[SparkQA]

Test build #65857 has finished for PR 15228 at commit caef89a.

• This patch fails Spark unit tests.
• This patch does not merge cleanly.
• This patch adds no public classes.