⏲ Add namespace parameter support to demos/stacks (so we can avoid default for easier cleanup, and TLS certs for any NS) #371

Technically, our demos can be installed into any namespace.

We do have a configuration option (supportedNamespaces) for both stacks and demos to restrict demos to certain namespaces though, and this is due to hard-coded things such as:

• TLS Certificate FQDNs that contain the namespace (example)
• Bootstrap server FQDNs (example)

This is a crutch, and could largely be solved by adding the namespace as a template parameter.

Proposal

Append the product_namespace as NAMESPACE to the end of the parameter list used for templating both stacks and demos.

Out of scope

The removal of the supportedNamespaces key. There might be other reasons to restrict the namespace of a demo that cannot be resolved via templated parameters.