feat: set this repo up for a Helm chart registry

[rauno56]

I cannot properly test the new workflow because of the very intricate setup with dispatches and everything. Thus I added the workflow here for testing.

❗ The workflow will be run and assets produced and uploaded to the release under "test-helm-assets-odigos.tgz". These assets will not be available through our current Helm Chart index. Anyone using our helm charts will not be affected with this PR. The current mode of Helm chart development completely stays the same. This contribution is solely for setting up a parallel workflow for testing.

Notable changes:

1. Set up a duplicate registry at https://odigos-io.github.io/odigos (note the lack of "-charts" suffix)
2. Bring charts into the same repo(this one here) as the code, since our application is tightly coupled with k8s assets anyway.
3. Integrate publishing Helm charts (to the new registry) into the "release" step of Odigos - until now, that step consisted of publishing CLI, now there's two outlets.
4. Simplify managing Helm Charts:
   • Remove the need to update the version(taken from the git tag)
   • Unify appVersion, chart version and image.tag values so that there's one less thing to mess up while releasing charts.
   • Automate the release process and reuse the same GitHub releases for the code, the CLI and helm charts.