CPS-1377: Spike - Investigate CPS Path search over multiple anchors under one dataspace

Requirement :

we need to search over data across multiple anchors for a given dataspace. for this requirement below changes are proposed 

New endpoint : GET http://localhost:8883/cps/api/v2/dataspaces/{dataspace-name}/nodes/query

parameters:

response :

[
{
  "test:bookstore": {
    "bookstore-name": "Chapters",
    "categories": [
      {
        "code": 1,
        "name": "SciFi"
      },
      {
        "code": 2,
        "name": "kids"
      }
    ]
  }
},
{"test:bookstore2": {
    "bookstore-name": "Chapters2",
    "categories": [
      {
        "code": 1,
        "name": "SciFi"
      }
    ]
  }
}
]

code changes as below: