Ability to list all resources in a given namespace

[jinnovation]

Currently, kele-list functionality is somewhat limited -- one group-version-kind + namespace combo, and that's it.

Let's add functionality analogous to kubectl get all that lists all of the resources in a given namespace.

With this, we can add a resource-specific suffix to kele-resource for namespaces e.g. [l]ist all resources.

Definition of Done

• Function implemented to list all resources in a given namespace using the kele-list interface
• Resource-specific suffix added to kele-resource allowing users to list all resources belonging to a specific namespace

[jinnovation]

Note that we've introduced kind-specific columns in #146 etc. When listing all resources, let's ignore kind-specific columns and only show the 'default' fields, e.g. name, namespace, etc.