Add a workflow for syncing a plugin from a git repository or file upload

[keithmanville]

We want to support the importing of plugins from external sources. This allows for:

• External development of plugins
• Sharing of plugins between deployments
• Management and automatic registration of Dioptra built-in plugins
• Automated registration of plugins (instead of manually uploading each file via a client)

To improve the import functionality, we need a way of tracking and updating externally managed plugins. This will be accomplished via a sync workflow in the restAPI, syncResources.

A new database table to track import source will be needed. It should include: id, name, source_type, url, hash, and timestamp(s).

Tasks:

• Design the schemas and endpoint(s) for the resourcesSync workflow in the REST API design doc on google drive
• Add the design to this issue once finalized
• Add new database table for tracking import source
• Implement the schema(s) and controller(s) for the workflow
• Implement the service layer with a single database commit

Definition of Done:

• Plugins can be synced from a file upload or git repository via a workflow
• New integration tests that cover plugin sync functionality are implemented
• All tests pass
• The feature is merged into dev