Supprt MCS as part of Xbench performance/deployment CLI

The performance group (DV) implemented CLI to
-create a cluster of AWS VMs with xpand or server software
-run performance benchmarks

This ticket will track adding MCS support to this CLI

DV will lead the project.

The MCS team will need to add or help add
-s3
-efs
-cmapi startup . I recommend new mcs CLI usage
-maxscale startup

Generic CLI future feature applicable to all topologies wish list
-stop/start
-change config : both cnf files and xml
-upgrade version of CS (for example from 6.4 to 20.08 ) . involves stop/upgrade binary/start
-elastic IP assigned to each developer to access VM