Remove information_content values from node_bindings in NodeNorm output

[gaurav]

While PR #231 fixed #229, it also introduced an odd change in NodeNorm's behavior: while we were previously not including any attributes in the resulting node_bindings, the fixed code now includes information content as well as potentially other attributes in the results node bindings. Here is some example output from babel-validation:

"node_bindings": {
  "n0": [
      {
        "id": "PUBCHEM.COMPOUND:130881",
        "attributes": [
          {
            "attribute_type_id": "biolink:has_numeric_value",
            "value": 100.0,
            "value_type_id": "EDAM:data_0006",
            "original_attribute_name": "information_content"
          }
        ]
      }
    ],
    "n1": [
      {
        "id": "MONDO:0001134",
        "attributes": [
          {
            "attribute_type_id": "biolink:has_numeric_value",
            "value": 83.0,
            "value_type_id": "EDAM:data_0006",
            "original_attribute_name": "information_content"
          }
        ]
      }
  ]
}

@uhbrar has requested that attributes passed in should be kept in results.[].node_bindings but new attributes should not be added. Note that IC values are also included in theknowledge_graph -- those should continue to be included. The relevant code is linked below:

NodeNormalization/node_normalizer/normalizer.py

Lines 96 to 111 in 029f3b9

	# get the information content value
	ic_attrib = await get_info_content_attribute(app, merged_binding['id'])
	# did we get a good attribute dict
	if ic_attrib:
	if 'attributes' in merged_binding and merged_binding['attributes'] is not None:
	merged_binding['attributes'].append(ic_attrib)
	else:
	merged_binding['attributes'] = [ic_attrib]
	node_binding_information = [
	"atts" if k == 'attributes'
	else (k, tuple(v)) if isinstance(v, list)
	else (k, v)
	for k, v in merged_binding.items()
	]