Unordered index.yaml entries for Helm Repository

[paolofacchinetti]

• What problem are you trying to solve?
  The index.yaml file generated by Nexus Repository for helm repositories has unordered chart entries.
  Helm indexes should instead have ordered entries based on the chart release version.

• Do you have a workaround you are using at present?
  No

• What feature or behavior is this required for?
  This is especially annoying when using tools such as ArgoCD to deploy charts from a Nexus Repository, because the UI shows a dropdown menu of unordered versions.

• How could we solve this issue? (Not knowing is okay!)
  Without knowing the internals of Nexus, I assume it could be done with a scheduled task akin to "rebuild maven metadata", maybe named "rebuild helm index.yaml"? The implementation is extremely straightforward, it's just a matter of reordering arrays of semver strings in descending order

• Tell us about your Nexus Repository deployment: what version, operating system, and database are you using?
  I'm using Nexus repository OSS 3.69.0-02 on a AmazonLinux2023 OS