"mongodb" module instrumentation is missing "destination" context

[trentm]

Spans emitted by the instrumentation of the mongodb module do not include the "destination" fields. The destination fields (specifically destination.service.resource) are used by Kibana's APM "Service Map" to display a node for downstream services.

Note that other MongoDB-related Node.js packages, like "mongoose", use the mongodb module, so are also affected.

E.g. here is an Elasticsearch span with "destination":

{
  "span": {
    "name": "Elasticsearch: POST /kibana_sample_data_logs/_search",
    "type": "db",
    "id": "891b874cc027aac5",
    "transaction_id": "8cc190e0bf8c117f",
    "parent_id": "8cc190e0bf8c117f",
    "trace_id": "a2ac5d4ddd06d0ea19ddd2fd8d8cd681",
    "subtype": "elasticsearch",
    "action": "request",
    "timestamp": 1606331068870301,
    "duration": 4.103,
    "context": {
      "db": {
        "type": "elasticsearch",
        "statement": "{\"size\":1,\"query\":{\"match_all\":{}}}"
      },
      "destination": {
        "service": {
          "name": "elasticsearch",
          "resource": "elasticsearch",
          "type": "db"
        },
        "address": "localhost",
        "port": 9200
      }
    },
    "sync": false,
    "outcome": "unknown"
  }
}