[Backport 2.16] Error visibility: Modifying error logs and logging more details about errors received from remote service

[opensearch-trigger-bot]

Backport 441af6e from #3337

[dhrubo-os]

/__w/ml-commons/ml-commons/ml-algorithms/src/main/java/org/opensearch/ml/engine/tools/SearchIndexTool.java:119: warning: [removal] AccessController in java.security has been deprecated and marked for removal
                        String doc = AccessController.doPrivileged((PrivilegedExceptionAction<String>) () -> {
                                     ^
/__w/ml-commons/ml-commons/ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java:174: error: cannot find symbol
            log.error("Remote server returned exception with status code: {} and body: {}", statusCode, body);
                                                                                                        ^
  symbol:   variable body
  location: class MLSdkAsyncHttpResponseHandler

why do we need to backport to 2.16 branch?