Enable metrics gathering & data visualisation of benchmark test results

[ksatchit]

Enable data visualisation of the benchmark test results with appropriate metrics & graphs. While a starting point could be to use simple plotting utilities such as gnuplot, which can derive necessary data (metrics) from the tool-specific log files, the need is to have a single source/webpage with all relevant plots to aid analysis and interpret the results.

This could be achieved using standard tools like grafana with metrics being collected from services like Prometheus

[ksatchit]

One part of the solution to the above problem will be addressed by the fix to this issue : openebs/openebs#392

This will enable us to get the "storage-side" metrics while a similar capability needs to be added for the "client-side", i.e., benchmark client-container as well