Associate artifacts with extracted models

[brandomr]

What's new

This PR addresses #297 by allowing models to be associated with artifacts (code) via an extracted_from relationship. Additionally this implements a new type of /provenance/search called models_from_code.

models_from_code accepts a model_id as the root_id and Model as root_type and returns an array of code artifacts from which the model was derived.

Considerations

Realistically, a model should only ever by extracted_from a single code artifact. In practice, this PR does not implement any verification that such a relationship exists--in other words someone could associate a model as being extracted from multiple code artifacts ☹️

Adding this validation is off the table for the time being but should be implemented during an overall refactor of provenance.

Known usage

This functionality is assumed/required by DARPA-ASKEM/knowledge-middleware#7

How to test this PR

1. Ensure you have a model and an artifact in TDS
2. Add a provenance relation:

POST /provenance
{
        "relation_type": "EXTRACTED_FROM",
        "left": "model_id",
        "left_type": "Model",
        "right": "articat_id",
        "right_type": "Artifact"
} 

3. Use the models_from_code provenance search to verify the relationship:

POST /provenance/search?search_type=models_from_code
{
            "root_id": model_id,
            "root_type": "Model"
}

4. Ensure that the result is [artifact_id] to successfully confirm that the source artifact from which the model was extracted is contained in the TDS response.

[brandomr]

Provenance is pretty much a mess right now and I think if we can determine which (if any) capabilities Uncharted currently uses @toddroper we can refactor around that. Somehow simple things like: "find the source code from which this model was extracted" are complicated and there are 2 sources of truth. Let's get to the bottom of how /provenance is currently used in the HMI--if at all--this week so we can rip out what we aren't using and build it back piece by piece as needed.