out_azure_kusto: support for otel log schema

[dceravigupta]

As outlined in the issue below, when the out_azure_kusto plugin was used alongside the in_opentelemetry plugin, it previously generated multiple logs for each incoming OTEL log. For instance:

[62] v1_logs: [[-1.000000000, {"schema"=>"otlp", "resource_id"=>0, "scope_id"=>11}], {"resource"=>{"attributes"=>{"telemetry.sdk.name"=>"opentelemetry", "telemetry.sdk.language"=>"dotnet", "telemetry.sdk.version"=>"1.8.1", "service.name"=>"unknown_service:dotnet"}}, "schema_url"=>"", "scope"=>{"name"=>"Microsoft.Extensions.HttpClient.Logging.Internal.HttpLoggingHandler"}}]
[63] v1_logs: [[1741372257.966227535, {"otlp"=>{"observed_timestamp"=>1741372257825108400, "timestamp"=>1741372257825108400, "severity_number"=>17, "severity_text"=>"Error", "attributes"=>{"resolved_host"=>"<some url>.com", "httpMethod"=>"GET", "httpHost"=>"<removed>", "httpPath"=>"<removed>", "duration"=>274, "{OriginalFormat}"=>"{httpMethod} {httpHost}/{httpPath}", "httpStatusCode"=>401}, "trace_flags"=>0}}], {"message"=>"GET <removed>"}]
[64] v1_logs: [[-2.000000000, {}], {}]

Fixes:
#10065

The fix implemented in this PR is take from similar fix done in out_splunk plugin: #10002

Output log after this change:

{
  "resource": {
    "attributes": {
      "telemetry.sdk.name": "opentelemetry",
      "telemetry.sdk.language": "dotnet",
      "telemetry.sdk.version": "1.8.1",
      "service.name": "unknown_service:dotnet",
    }
  },
  "schema_url": "",
  "scope": {
    "name": "Microsoft.Extensions.HttpClient.Logging.Internal.HttpLoggingHandler"
  },
  "otlp": {
    "observed_timestamp": 1743791176558409200,
    "timestamp": 1743791176558409200,
    "severity_number": 17,
    "severity_text": "Error",
    "attributes": {
      "resolved_host": "<removed>",
      "httpMethod": "GET",
      "httpHost": "<removed>",
      "httpPath": "<removed>",
      "duration": 36,
      "{OriginalFormat}": "<removed>",
      "httpStatusCode": 403
    },
    "trace_flags": 0
  }
}

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• Backport to latest stable release.

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

[dceravigupta]

@edsiper can you please take a look at this PR? It is based on the pr you did for out_splunk plugin: #10002

[dceravigupta]

@edsiper, @koleini , @fujimotos can one of you take a look at this tiny PR?

Once this is complete, I'm also planning to work on the following issues: #10066