CyColumn model should include listType for operations, and for CyJSONUtil

To address this bug:

Original description:

The JSON output representing columns for both CyREST Functions and Commands doesn't include listType for list columns.

For example, in galFiltered.sif, the following is the __Annotations column:

{
    "name": "__Annotations",
    "type": "List",
    "immutable": false,
    "primaryKey": false
}

An optional field, listType would make the type of list clear:

{
    "name": "__Annotations",
    "type": "List",
    "listType": "String",
    "immutable": false,
    "primaryKey": false
}

cytoscape / cyREST