chore: add debug logging for llm span type and openai operations (#14386)

This PR adds additional debug logging:
- Logging the llm span type
- Logging OpenAI operations when creating LLM spans

[MLOB-3526]
## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)


[MLOB-3526]:
https://datadoghq.atlassian.net/browse/MLOB-3526?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Author: XG-xin

ddtrace/llmobs/_integrations/base.py

@@ -65,6 +65,7 @@ def trace(self, pin: Pin, operation_id: str, submit_to_llmobs: bool = False, **k
             service=int_service(pin, self.integration_config),
             span_type=SpanTypes.LLM if (submit_to_llmobs and self.llmobs_enabled) else None,
         )
+        log.debug("Creating LLM span with type %s", span.span_type)
         # determine if the span represents a proxy request
         base_url = self._get_base_url(**kwargs)
         if self._is_instrumented_proxy_url(base_url):

ddtrace/llmobs/_integrations/openai.py

@@ -5,6 +5,7 @@
 
 from ddtrace._trace.pin import Pin
 from ddtrace.internal.constants import COMPONENT
+from ddtrace.internal.logger import get_logger
 from ddtrace.internal.utils.version import parse_version
 from ddtrace.llmobs._constants import CACHE_READ_INPUT_TOKENS_METRIC_KEY
 from ddtrace.llmobs._constants import INPUT_DOCUMENTS
@@ -30,6 +31,9 @@
 from ddtrace.trace import Span
 
 
+log = get_logger(__name__)
+
+
 class OpenAIIntegration(BaseLLMIntegration):
     _integration_name = "openai"
 
@@ -59,6 +63,7 @@ def trace(self, pin: Pin, operation_id: str, submit_to_llmobs: bool = False, **k
         traced_operations = ("createCompletion", "createChatCompletion", "createEmbedding", "createResponse")
         if operation_id in traced_operations:
             submit_to_llmobs = True
+        log.debug("Creating LLM span for openai operation: %s", operation_id)
         return super().trace(pin, operation_id, submit_to_llmobs, **kwargs)
 
     def _set_base_span_tags(self, span: Span, **kwargs) -> None: