Add a workflow for importing 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)

This will be implemented as a new workflow in the REST API, /workflows/resourcesImport.

Initially, all imported plugins will have a read-only lock applied. We will consider mechanisms for editing and reconciling changes in the future.

Initially, we will support importing from a archive (.zip, or .tar.gz) file upload or a git repository (no authentication support). We will consider other sources in the future.

Tasks:

• [x] Design the schemas and endpoint(s) for the resourcesImport workflow in the REST API design doc on google drive
• [x] Add the design to this issue once finalized
• [x] Implement the schema(s) and controller(s) for the workflow
• [ ] Add new database table for tracking import source
• [ ] Implement the service layer with a single database commit
• [ ] Write documentation for the structure of an importable plugin

Definition of Done:

• [ ] The contract for the structure of a plugin is documented in the sphinx docs
• [ ] Plugins can be imported from a file upload or git repository via a workflow
• [ ] New integration tests that cover plugin import functionality are implemented
• [ ] All tests pass
• [ ] The feature is merged into dev

[keithmanville]

A workflow for importing resources from a file or git repo. It will handle the importing of the following resources:

• Plugin
• PluginFile
• PluginParameterType
• EntryPoint

POST /workflows/resourcesImport payload:

{
  "groupId": int,  # the group that will own the imported resources
  "sourceType": Enum("upload", "git"),  # the source of the import
  "uri": str | None,  # the uri of the git repository (if sourceType is git)
  "data": bytes | None,  # the uploaded archive file (if sourceType is upload)
  "readOnly": bool,  #  whether imported resources should get a readonly lock
  "resolveNameConflicts", Enun("fail", "overwrite")  # behavior for resolving name conflicts
}