[ML] validate datafeed composite aggregation support in Single metric viewer

[benwtrent]

Describe the feature:
Validations around if an aggregated datafeed can be shown in SMV should include composite aggregations.
Describe a specific use case for the feature:
With elastic/elasticsearch#69970 it will be possible for users to create datafeeds that use composite aggregations.

The current validations ASSUME a date_histogram parent aggregation. But, it is now possible that the top level agg is composite.

So, along with the typical sub-agg validations (nested terms, etc.), an additional validation needs to be done for composite.

The UI should make sure that the composite sources are terms and date_histogram only. While it is possible to execute a filter query for the other source types, that logic is not in kibana yet.

Here is a validate data feed:

{
  "job_id": "farequote-composite",
  "indices": [
    "farequote"
  ],
  "aggregations": {
    "buckets": {
      "composite": {
        "size": 1000,
        "sources": [
          {
            "time": {
              "date_histogram": {
                "field": "time",
                "fixed_interval": "360s",
                "time_zone": "UTC"
              }
            }
          },
          {
            "airline": {
              "terms": {
                "field": "airline"
              }
            }
          }
        ]
      },
      "aggregations": {
        "time": {
          "max": {
            "field": "time"
          }
        },
        "responsetime": {
          "avg": {
            "field": "responsetime"
          }
        }
      }
    }
  }
}

Here is one that wouldn't really be visible in SMV (based only on composite sources)

{
  "job_id": "farequote-composite",
  "indices": [
    "farequote"
  ],
  "aggregations": {
    "buckets": {
      "composite": {
        "size": 1000,
        "sources": [
          {
            "time": {
              "date_histogram": {
                "field": "time",
                "fixed_interval": "360s",
                "time_zone": "UTC"
              }
            }
          },
          {
            "airline": {
              "terms": {
                "field": "airline"
              }
            }
          },
          {
            "tile": {
              "geotile_grid": {
                "field": "destination.position"
              }
            }
          }
        ]
      },
      "aggregations": {
        "time": {
          "max": {
            "field": "time"
          }
        },
        "responsetime": {
          "avg": {
            "field": "responsetime"
          }
        }
      }
    }
  }
}

Note the additional sources entry of geotile_grid

[elasticmachine]

Pinging @elastic/ml-ui (:ml)

[qn895]

This validation is added now in #96348