Story

In the future, and that's why this story has a lower priority, we want to fetch all plugins for a plugin list.

For that, the MarketplaceAPI should allow the UI to get all all plugin lists and also all related plugins to a list (like getPluginsForPluginList).

Of course, the API and all implementations should support this. (See also RHIDP-5329)

This should story add "full support" for PluginLists:

1. Get a Plugin by name (for the case it doesn't exist yet)
2. Get a PluginList by name
3. Get all PluginLists (incl. pagination, sorting and filters from RHIDP-5329)
4. Get all Plugins for a PluginList (name)

Of course, this requires to update the API and all implementations.

For the last call, getting all Plugins for a PluginList: having an optional pagination would be nice. Otherwise, we should document that this API requires pagination so that it's clear for the UI to load multiple pages is necessary.

Background

Please align the API with:

1. https://backstage.io/docs/features/software-catalog/software-catalog-api/
2. https://backstage.io/docs/next/reference/catalog-client.catalogapi.getentities/
3. https://backstage.io/docs/next/reference/catalog-client.catalogapi.queryentities/

Dependencies and Blockers

None

Acceptance Criteria

1. Updated API, implementation
2. Added or extended unit tests
3. Documentation