[exporter/opensearch] Align emitted data's schema to match OTLP

[YANG-DB]

Component(s)

exporter/opensearch

Describe the issue you're reporting

The current OpenSearch implementation has some specific propriety mapping related to the SS4O schema
This is not very simple to maintain this propriety dependency in addition to the evolving OTLP schema .

We would like to remove any non-otlp related schema features, is such exist they should be added as part of the OTEL-transform processor (https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/processor/transformprocessor/README.md)

Indexing Option should be removed away from the data itself into a metadata wrapper to instruct the target index

This should also be able to support both standard index and data-stream