Feature requests for enabling Azure Arc-enabled Kubernetes cluster extensions

[synicalsyntax]

The Azure Arc-enabled Kubernetes team is hoping to utilize Porter Operator automate in-cluster management of installations. However, there are several features we're missing that we'd like to have moving forward:

• If a user manually changes installation state (e.g. by deleting the namespace created in the namespace), the Porter Operator should be able return the installation to its original desired state.
• It would be nice to support optional parameters; currently, if an extraneous parameter not mentioned in the bundle manifest is provided, Porter errors out.
• Porter Operator doesn't attempt to reinstall applications of the same name after a previous installation with the same name was uninstalled. A Slack discussion suggested "supporting a method to totally remove an installation from the backing store" to resolve this.
• It would be ideal to allow certain versions of mixins to be installed in the manifest (instead of pulling in some latest version) to meet security requirements.

cc @jhmadhav @RamyasreeChakka