chore: Migrate Helm chart from the eks-chart repository

[bryantbiggs]

Issue #, if available:

Description of changes:

• Add Helm chart from eks-charts repository
  • This chart should be published from this repository primarily due to 2 reasons:
    1. To deploy new versions of aws-sigv4-proxy-admission-controller artifacts in unison - both the image and the helm chart
    2. It is where the maintainers primarily operate and where users should come for feature requests, bugs/issues, documentation, etc.

The container image is already being published to Public ECR, the same should be done for the Helm chart which then allows both the image and the chart to be published together to Public ECR

We have opened a PR on the eks-charts repo to deprecate and remove this chart and direct users to this project going forward - aws/eks-charts#1170

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.