feat: import resources from git repo or archive file

[keithmanville]

resolves:

• Add a workflow for importing a plugin from a git repository or file upload #588
• Create a simple "hello-world" plugin #591

[keithmanville]

Basic import functionality is now working. To test it with the included hello world plugin, go to the /api/v1/workflows/resourceImport endpoint in swagger, then either import via git or upload:

for git, set sourceType to "git" and gitUrl to https://github.com/usnistgov/dioptra#workflow-import

for file upload, first create an archive containing the necessary files (from the root dioptra dir in this branch)

tar -czf plugins.tar.gz -C . plugins examples/hello-world.yaml dioptra.toml

then set sourceType to "upload" and select the archive you created.

[keithmanville]

TODO: update commented example in docs to match the example.

[keithmanville]

I think this is a bug in marshmallow swagger docs. When the schema is used as form data, it ignores data_key in the swagger UI.

[keithmanville]

should be:

    yield f
    f.close()

[keithmanville]

converting back to Draft.

Needs to update the client to support the new workflow. Tests should be updated to use client.

Blocked by #694