[FEATURE]: Add component types to better support container orchestration environments

The list of valid component types is rather limited and this makes tools such as Dependency Track less useful when trying to work with container orchestration environments - essentially everything has to be either Application or Container.

I would like to propose:

- Cluster
A collection of components that function together as a unit.

For my purposes this would be either a Kubernetes or Swarm cluster, but it would serve equally in other situations.
"Environment" would work as well as "Cluster", but I think "Cluster" is more generically useful.

- Service
An abstract grouping of software components that provides some kind of end point for use by other components.