Create endpoint in backend to retrieve locations/opportunities data

[mahekagg]

-endpoint will retrieve all data for locations and opportunities

• write unit tests
• GET api/v1/map/sites

• "type": "FeatureCollection",
  "name": "sites",
  "features: [
    {
      "type": "Feature",
      "properties": {
        "id": INT,
        "name": STRING,
  

"resources": [{resource_id, name, description, amount, type}]
"opportunities": [{id, name, description, organizer name, organizer email}],

  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      LONG,
      LONG
    ]
  }
},
...

]
}```