If `collection` is missing from ingesting Item, a low-level OpenSearch client error occurs rather than a clear invalid response

[philvarner]

If collection is missing from ingesting Item, a low-level OpenSearch client error occurs:

{
    "level": "error",
    "message": "Error while ingesting item Missing required parameter: index",
    "name": "ConfigurationError",
    "stack": "ConfigurationError: Missing required parameter: index\n    at IndicesApi.indicesExistsApi [as exists] (/var/task/index.js:6779:17)\n    at writeRecordToDb (/var/task/index.js:62664:41)\n    at processTicksAndRejections (node:internal/process/task_queues:96:5)\n    at async ingestItems (/var/task/index.js:62727:16)\n    at async Runtime.handler (/var/task/index.js:63194:21)"
}

The code path here is that the Item is checked that it has a Feature type and then the collection is retrieved to check in an index with that name exists, without checking that the collection field is actually defined.

Instead, there should be a validation that the collection field is defined.