Ingest should look at JSON type field for Collection/Item determination rather than field heuristic

[philvarner]

Ingest currently determines if an input JSON is a Collection or an Item based on a heuristic of it it has an extent or a geometry:

  if (data && data.hasOwnProperty('extent')) {
    index = COLLECTIONS_INDEX
  } else if (data && data.hasOwnProperty('geometry')) {
    index = data.collection
  } else {
    return null
  }

However, STAC API 1.0.0 requires the field type for both Item and Collection. This should be used for this determination instead.