[Feature Request] Configurable Document Mapping in Pull Based Ingestion

[imRishN]

Is your feature request related to a problem? Please describe

• Add id_field, version_field, op_type_field settings to IngestionSource
• Implement a new message mapper (or extend existing) that uses these settings
• This alone eliminates the need for an external preprocessing layer for the message format problem

Describe the solution you'd like

#20677

Related component

Indexing

Describe alternatives you've considered

No response

Additional context

#20677