PROPOSAL - refactor the templates to be more composable to reduce the amount of repetition

[mrsimonemms]

At the moment, the structure of the templates is <cloud>-<vcs> (eg, aws-github or civo-gitlab). IMO, this means that there will be an awful lot of duplication in these templates. For example, when I did the recent GCP cluster work (#769) it was only for GitHub - the likelihood is that most (if not all) of this will be identical for GitLab.

This is an additional maintenance burden on our small team that we don't need.

├── akamai-github
├── aws-github
...<lots-more>
└── vultr-gitlab

I would advocate for refactoring this repo so that it incorporates a common folder. This would be for each level. My proposed structure will be something like this:

├── common 
│   ├── cloud  # One folder for each cloud provider, eg `aws`, `civo`, `gcp` etc
│   │   ├── aws # Everything in here is copied to every "aws" gitops
│   │   └── <...>
│   ├── template # Everything in here is copied to every gitops
│   └── vcs # One folder for each VCS provider, eg `github`, `gitlab` etc
│       ├── github # Everything in here is copied to every "github" gitops
│       └── <...>
└── template # Each of the folders we currently have
    ├── akamai-github
    ├── aws-github
    ├── <...>
    └── vultr-gitlab

Pros

• Reduce the amount of duplication we have
• Make it easier to rollout updates

Cons

• ~The gitops repo for the user is no longer a fork of the gitops-template repo~
• How would we maintain backwards compatibility?