[BUG] Invalid Subfield Document Created When Using DOT Notation

[forestmvey]

Describe the bug
When using DOT notation in a field while creating a document we get a document that doesn't match the mapping. Dynamic mapping is successful in matching the supplied field as a subfield, but document parsing fails to match this mapping.

To Reproduce
Steps to reproduce the behavior:

1. Create a doc with a dot in a field name:

curl -X POST "localhost:9200/test/_doc/?pretty" -H 'Content-Type: application/json' -d '{ "account.number" : 42 }'

2. Verify mapping created for document properly recognizes the account.number as a subfield:

curl -X GET "localhost:9200/test" -H 'Content-Type: application/json'

{
    "test": {
        "aliases": {},
        "mappings": {
            "properties": {
                "account": {
                    "properties": {
                        "number": {
                            "type": "long"
                        }
                    }
                }
            }
    ...
 }

3. Query document and see that the original source value is used rather than subfield value:
   Query:

curl -X POST "localhost:9200/test/_search" -H 'Content-Type: application/json' -d '{"_source":{"includes":["*"]}}'

{
    ...,
    "hits": [
    {
       "_index": "test",
        "_id": "",
        "_score": 1.0,
        "_source": {
           "account.number": 42
       }
    }] 
}

Expected behavior
Document data should reflect mapping with account.number field as subfield. Expected output should look like:

{
    ...,
    "hits": [
    {
        "_index": "test2",
        "_id": "1",
        "_score": 1.0,
        "_source": {
            "account": {
                "number": 42
           }
         }
   }]
}

Plugins
opensearch-sql

Screenshots
N/A

Host/Environment (please complete the following information):

• OS: MacOS
• Version 13.4.1

Additional context
OpenSearch Commit: ca74aac1482718a864676e27707bb77b7c168e6f