Add test for DeepResearch and telemetry.

[nick863]

Description

Please add an informative description that covers that changes made by the pull request and link all relevant issues.

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All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

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• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull Request Overview

This PR adds telemetry test support for the DeepResearch tool functionality. The changes enable comprehensive testing of telemetry instrumentation when using DeepResearch capabilities within the Azure AI Agents SDK.

Key changes include:

• Addition of DeepResearch tool test methods in both sync and async instrumentor test classes
• Enhanced telemetry verification logic to handle DeepResearch-specific spans and annotations
• Improved error messaging in the trace verifier for better debugging

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test_ai_instrumentor_base.py	Adds DeepResearch tool helper method and updates span checking logic for annotations and variable span counts
test_ai_agents_instrumentor_async.py	Implements async test for DeepResearch tool telemetry with content recording
test_ai_agents_instrumentor.py	Implements sync test for DeepResearch tool telemetry with content recording
gen_ai_trace_verifier.py	Improves error message formatting for better debugging of key mismatches
_ai_agents_instrumentor.py	Adds comment explaining DeepResearch tool handling
assets.json	Updates asset tag for test recordings