Rethink client and cluster installation workflow

[robertglonek]

• Want the supported components and the “best way to extend” aerolab to be basically the same mechanism…
• Establish convention for where to download artifacts (helps with exploring deployed machines)
• node_exporter && Prometheus config (perhaps dynamic config?)
• Can everything be a cluster of node groups (under node-group create/list/etc) and then added capabilities/features to make cluster commands and different client commands?
• Can we add an option to extend features/capabilities with templates aerolab can be fed?
• Introduce Capability concept
• A way for a capability to communicate what OS versions and architectures it needs?
• Remove old client installation procedure (8.0) - or keep client/cluster commands but replace them so they will use the node-group system.