Install eoAPI on EKS

[aliziel]

The eoAPI Helm chart has had a couple bigger releases recently with a lot of improvements. We've been running them (almost) in parallel on our development cluster and should be able to start with the latest (v0.7.1).

Basic install scripts are included in hotosm/k8s-infra#16.

Further work:

• Automate deploy
• Look into bridging TF-managed values
  • Existing values are passed as input to chart installation
  • Included in README (build: install eoAPI chart k8s-infra#17)
• Add support chart

[aliziel]

Was going to open hotosm/k8s-infra#17 on Monday to avoid any weekend pressure, but I didn't consider write access. Its ready, it just won't start turning green until the cluster is available (#184 (comment)).

The PR adds a Helm CI workflow, a support chart, and documentation. Helmfile was added as a declarative intermediary for the longer-term GitOps plans. It'll take care of revising only on change detection, orchestrating dependencies, and injecting environment variables without a bunch of extra scripting. If its not preferred, however, it can be removed:

1. Remove the helmfile action. Unless a replacement action provides Helm, it will need to be setup on the runner.
2. Chart order should be PostgresOperator → eoAPI → eoAPI support
3. The role defined in TF for bucket access should be passed to the eoAPI chart release
4. The support chart should only be added once TLS is set up on eoAPI (documented in build: install eoAPI chart k8s-infra#17)