Feature Goal

We need to move the janus-idp/cli functionality upstream to ease maintenance and provide this ability to upstream users as there's a lot of demand for dynamic plugins.

Also we can use this opportunity to refine the CLI UX as using npx @janus-idp/cli package export-dynamic-plugin can be currently a little bit cumbersome. 

For example

• flag description can be confusing for someone who is not yet familiar with dynamic plugins
• there should be a flag that allows you to specify path to plugin sources so user don't need to always `cd` into a plugin source directory
• this command could be also "workspace aware" similarly how it is done in package-dynamic-plugins
• A flag that controls the output directory for the exported dynamic plugin package would also be helpful

Acceptance Criteria

TBD