feat(llmobs): add prompt and name arguments to annotation context

[lievan]

This PR adds support for prompt and name arguments to annotation_context.

Because prompt depends on span kind being equal to llm, we also need to do a small refactor of annotate. Prompts will be tagged in annotate before span kind is checked. The span kind checked is then done at trace processing time, where we will log a warning and drop the prompt field for any non-LLM span kinds.

Checklist

• 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
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• 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 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

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-09-20 16:19:31

Comparing candidate commit ed7e205 in PR branch evan.li/enhance-annotation-context with baseline commit baac738 in branch main.

Found 3 performance improvements and 0 performance regressions! Performance is the same for 353 metrics, 48 unstable metrics.

scenario:iast_aspects-aspect_iast_do_lower

• 🟩 max_rss_usage [-2.425MB; -2.113MB] or [-8.155%; -7.108%]

scenario:iast_aspects-aspect_iast_do_modulo

• 🟩 max_rss_usage [-2.358MB; -2.088MB] or [-7.932%; -7.024%]

scenario:iast_aspects-aspect_iast_do_str

• 🟩 max_rss_usage [-2.663MB; -2.129MB] or [-8.949%; -7.155%]

[github-actions]

CODEOWNERS have been resolved as:

releasenotes/notes/annotation-context-modify-name-and-prompt-cc74b3b268983181.yaml  @DataDog/apm-python
ddtrace/llmobs/_llmobs.py                                               @DataDog/ml-observability
ddtrace/llmobs/_trace_processor.py                                      @DataDog/ml-observability
tests/llmobs/test_llmobs_service.py                                     @DataDog/ml-observability
tests/llmobs/test_llmobs_trace_processor.py                             @DataDog/ml-observability

[Yun-Kim]

Why is it non-deterministic?

[Yun-Kim]

Let's make documentation for this in our public docs, probably next to Annotate a span.

[Yun-Kim]

Can we remove this line?

[Yun-Kim]

Suggested change

	LLM Observability: Introduces `prompt` and `name` arguments to LLMObs.annotation_context to support setting the `name` and `prompt` of integration generated spans.
	LLM Observability: Introduces `prompt` and `name` arguments to ``LLMObs.annotation_context()`` to support setting an integration-generated span's name and `prompt` field.