feat: jfrog plugin + helm upload handler

[jakobmoellerdev]

What this PR does / why we need it

Implements a JFrog Plugin that contains an uploader that is able to upload to JFrog Helm Chart Repositories (different from OCI).

Example Reference Upload configuration:

- type: credentials.config.ocm.software
  consumers:
  - identity:
      type: JFrogHelm
      hostname: int.repositories.cloud.sap
    credentials:
    - type: Credentials/v1
      properties:
        username: "your-user-here"
        password: "your-token-here"
- type: uploader.ocm.config.ocm.software
  registrations:
  - name: plugin/jfrog/JFrogHelm
    artifactType: helmChart
    priority: 200
    config:
      type: JFrogHelm/v1alpha1
      url: "your-artifactory-url-here"
      repository: "your-repository-here"
      # reindexAfterUpload: true # in case you want to force a reindex, requires admin repository credentials, off by default

The plugin will be installable with

ocm install plugin ghcr.io/open-component-model/ocm//ocm.software/plugins/jfrogplugin

as it is added to our parallel build list.

Since during development (while this PR does not get merged and we dont have an RC) you cannot use this command, you can choose to either push your own version of the plugin (there are commands in the new makefile), or you can run (also in the new makefile):

make -C components/jfrogplugin install

which will do a build and install locally so you can use it without fetching it remotely

Once added, you can run something like

ocm plugin get jfrog -oyaml
---
element:
  description: "ALPHA GRADE plugin providing custom functions related to interacting
    with JFrog Repositories (e.g. Artifactory).\n\nThis plugin is solely for interacting
    with JFrog Servers and cannot be used for generic repository types.\nThus, you
    should only consider this plugin if\n- You need to use a JFrog specific API\n-
    You cannot use any of the generic (non-jfrog) implementations.\n\nExamples:\n\nYou
    can configure the JFrog plugin as an Uploader in an ocm config file with:\n\n-
    type: uploader.ocm..config.ocm.software\n  registrations:\n  - name: plugin/jfrog/JFrogHelm\n
    \   artifactType: helmChart\n    priority: 200 # must be > 100 to be used over
    the default handler\n    config:\n      type: JFrogHelm/v1alpha1\n      # this
    is only a sample JFrog Server URL, do NOT append /artifactory\n      url: int.repositories.ocm.software
    \n      repository: ocm-helm-test\n"
  forwardLogging: true
  pluginName: jfrog
  pluginVersion: 0.20.0-dev+962ef1469035fbd7b855dff1ccb6ddfc06269745
  shortDescription: jfrog plugin
  uploaders:
  - constraints:
    - artifactType: helmChart
      contextType: ""
      mediaType: ""
      repositoryType: ""
    description: upload artifacts to JFrog HELM repositories by using the JFrog REST
      API.
    name: JFrogHelm
  version: v1

to introspect it.

The plugin is now able to be used by OCM.

The plugin registers itself for the mediaTypes of a Helm Chart TGZ as well as OCI artifacts to convert them. Notably, the OCI artifact conversion is lossy because the provenance data is omitted, so back and forth conversion while maintaining digests might not always be possible in a fully trusted environment

Which issue(s) this PR fixes

fix #1116

[Skarlso]

Initial review before starting to play around with this.

[Skarlso]

Well done! :) Thanks for bearing with me. :D