Display contributing group for experimental evidence

[dustine32]

Show the group(s) for an IBA annotation that contributed the supporting experimental annotations. Example:

    {
        "gene": "UniProtKB:Q07889",
        "gene_symbol": "SOS1",
        "gene_name": "Son of sevenless homolog 1",
        "term": "GO:0005085",
        "slim_terms": [
            "GO:0098772"
        ],
        "qualifiers": "enables",
        "evidence": [
            {
                "with_gene_id": "UniProtKB:Q13972",
                "references": [
                    "PMID:27856453"
                ]
            },
        ]
    }

This Contributor value is actually the providedBy in the GAF. We should pull this into the annotation JSON in a new "group" field on each "evidence" object:

            {
                "with_gene_id": "UniProtKB:Q13972",
                "references": [
                    "PMID:27856453"
                ],
                "group": "BHF-UCL"
            },

[dustine32]

Closing since this is working in data conversion as well as the UI.