ENG-6229 Created a benchmark test for Materialized Views

This benchmark compares the performance overhead for inserts and deletes in a table with materialized views and a table without materialized views.
ENG-6229 Modified code to exit with correct error code
ENG-6229 Fixed a number of issues with the test and added a group field for more test flexibility
ENG-6229 Fixed the schema to properly use the new group field
ENG-6229 Fixed indentation issue and made some changes to add clarity
ENG-6229 Fixed indentation issue
Merge pull request #1387 from VoltDB/ENG-6229

ENG-6229 Created a benchmark app for visualizing the performance overhead of tables with materialized views