Overview (aka. Goal Summary)

In upstream backstage, we should have a backstage CLI command to export plugins as dynamic plugin, similarly to what is done by our `rhdh-cli plugin export` command.   

Goals (aka. expected user outcomes)

Not depend anymore on any RHDH-specific CLI to export dynamic plugins and run them on upstream backstage.

Requirements (aka. Acceptance Criteria):

Have a backstage CLI command that does is fully compatible with both upstream backstage and RHDH needs.