Implement the Package Manager API to use for the IDE

[radeusgd]

Summary

The API that is to be designed in #1764 has to be implemented and connected with the package-manager component.

Value

• The IDE can use the package-manager.

Specification

• The API has to be implemented as described in the documentation.
• The endpoints need to be connected to the package-manager component.
• Implement logic related to the endpoints:
  • Listing dependencies of the project (probably can be done by looking at the loaded libraries or alternatively may require parsing the files).
  • Modifying edition settings.
  • Notifications for downloads integrated with imports.
  • Other designed endpoints.
  • This does not include handling the content roots which have their own task: Implement Missing Parts of Multiple Content Roots #1780.

Acceptance Criteria & Test Cases

• The API is tested as much as reasonably possible.