Description of problem:

The "Bump Version" GitHub workflow in the rhdh-chart repo only handles the "backstage" Chart using a `/bump [patch|minor|...]` comment: https://github.com/redhat-developer/rhdh-chart/blob/main/.github/workflows/bump-version.yaml#L99
Now that the repo contains additional charts, we should provide a way to specify which chart to bump version for.

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. On a PR created (branch needs to be in the same rhdh-chart repo, like Renovate PRs), comment with `/bump patch`.

Actual results:

You will notice that only the "backstage" chart has been bumped. This makes sense on some PRs updating the backstage chart, but won't make sense if the PR is updating a different chart.

Expected results:

Extend the comment handling to support passing a chart name, like:

`/bump orchestrator-infra [patch|minor|...]`

or

`/bump backstage [patch|minor|...]`

We don't need to maintain backward compatibility, as this is for our own internal use case.

Reproducibility (Always/Intermittent/Only Once):

Always