[feature] add elapsed time in the json schema for all types

[gabrielcsapo]

Now that we have standardized the output schema it would be great to include timing information to track how long certain tasks are taking. Then the reporter provider can use that data to either present it or not.

Currently a task has the current schema looks like the following:

https://github.com/checkupjs/checkup/blob/master/packages/core/src/schemas/task-result-schema.json#L63

"properties": {
  "info": {
    "type": "object",
    "properties": {
      "taskName": {
        "type": "string"
      },
      "friendlyTaskName": {
        "type": "string"
      },
      "taskClassification": {
        "type": "object",
        "properties": {
          "category": {
            "type": "string"
          },
          "group": {
            "type": "string"
          }
        },
        "required": ["category"]
      }
    },
    "required": ["taskName", "friendlyTaskName", "taskClassification"]
  }
}

I propose adding a time object to info property:

"time": {
  "type": "object",
  "properties": {
    "elapsed": {
      "type": "number"
    },
  },
}

[scalvert]

I don't believe this makes sense for the JSON schema to contain this information. We do provide a way for task authors to determine how long a task runs,

DEBUG="checkup:task" checkup --task <yourTask>

and I believe this is the right way to think about this. Task authors should be responsible for determining the optimal execution of their tasks, and can do so via debug.

Hope this makes sense.

[scalvert]

@rwjblue any thoughts on this?