EVA-1077 and EVA-1092 - Read workloads from configuration files + other changes
Created by: sundarvenkata-EBI
Made the following updates
- Facilitate reading of workload configuration from JSON files
- Better formatting of failure messages in Samplers
- Switch to separate insert into a reverse lookup table instead of materialized views in Cassandra due to possible deprecation of materialized views - https://www.mail-archive.com/user@cassandra.apache.org/msg54073.html
- Make insertion logic somewhat uniform across databases and add timestamps to avoid collisions during multiple runs
- Add explicit majority "Read Concern" for MongoDB reads since that is not the default for versions >= 3.4