view privileges support

[HaydenHan]

In ranger-hive-plugin，view permissions and original table permissions are separated。
So you can create views on your table with specified conditions（specify partitions, rows, columns），then grant views privilege to some users but not the original table。

After actual verification and reading code，i find spark-authorizer do not support the feature。

Do you think this feature is necessary? In fact, I have already supported it by modifying
the code. If you think it is necessary, I am happy to share the code and ask for your guidance.

[yaooqinn]

LGTM, feel free to submit a pr

[HaydenHan]

Both spark and spark-authorizer need to be modified.

directions：
spark LogicalPlan will apply rule extensions “org.apache.spark.sql.catalyst.analysis.EliminateView” before apply rule “org.apache.spark.sql.catalyst.optimizer.RangerSparkAuthorizerExtension”。
“EliminateView” will remove the view information，so when “RangerSparkAuthorizerExtension” builder privileges，it can not get the view Information。In fact， "RangerSparkAuthorizerExtension" does not to get the view informations at all.

modified:
1, in spark，before apply rule “EliminateView”，we can store the view information
2, in spark-authorizer, we can get the view information when build privileges