Modify how Python dicts and lists get stored and read into/from Neo4j

[maxsibilla]

Currently we are storing a stringified Python literal into Neo4j rather than actual JSON.

• Modify _build_properties_map in both schema_neo4j_queries.py and app_neo4j_queries.py to replace

 escaped_str = str(value).replace("'", r"\'")

with

escaped_str = json.dumps(value)

• Write a new method that replaces hubmap_commons.convert_str_literal to utilize json.loads(...) instead of ast.literal_eval(...) as the data being grabbed out of Neo4j will no longer be Python literals

• In any normalize function such as normalize_entity_result_for_response and _normalize_metadata where hubmap_commons.convert_str_literal is called we will want to replace with the new function mentioned above