[Python APIView] update "duplicate IDs" message to be more descriptive and user-actionable

This is hard to figure out what the issue is.
e.g.
```
2026-04-10 21:50:01,734 [INFO] azure-sdk-tools: Using prebuilt wheel directory: /mnt/vss/_work/1/a
2026-04-10 21:50:01,766 [INFO] root: Found whl azure-ai-agentserver-responses/azure_ai_agentserver_responses-1.0.0b1-py3-none-any.whl
2026-04-10 21:50:01,767 [INFO] azure-sdk-tools: Running apistub ['-m', 'apistub', '--pkg-path', '/mnt/vss/_work/1/a/azure-ai-agentserver-responses/azure_ai_agentserver_responses-1.0.0b1-py3-none-any.whl', '--out-path', '/mnt/vss/_work/1/a/azure-ai-agentserver-responses'].
Traceback (most recent call last):
File "/opt/hostedtoolcache/Python/3.10.19/x64/lib/python3.10/runpy.py", line 196, in _run_module_as_main
return _run_code(code, main_globals, None,
File "/opt/hostedtoolcache/Python/3.10.19/x64/lib/python3.10/runpy.py", line 86, in _run_code
exec(code, run_globals)
File "/mnt/vss/_work/1/s/.venv/azure-ai-agentserver-responses/.venv_apistub/lib/python3.10/site-packages/apistub/__main__.py", line 4, in
console_entry_point()
File "/mnt/vss/_work/1/s/.venv/azure-ai-agentserver-responses/.venv_apistub/lib/python3.10/site-packages/apistub/__init__.py", line 30, in console_entry_point
apiview = stub_generator.generate_tokens()
File "/mnt/vss/_work/1/s/.venv/azure-ai-agentserver-responses/.venv_apistub/lib/python3.10/site-packages/apistub/_stub_generator.py", line 224, in generate_tokens
self.check_unique_line_ids(apiview)
File "/mnt/vss/_work/1/s/.venv/azure-ai-agentserver-responses/.venv_apistub/lib/python3.10/site-packages/apistub/_stub_generator.py", line 257, in check_unique_line_ids
raise ValueError(f"Duplicate LineIds found: {duplicate_ids}")
ValueError: Duplicate LineIds found: ['azure.ai.agentserver.responses.FoundryStorageSettings.build_url.param(extra_params)']
2026-04-10 21:57:54,039 [ERROR] azure-sdk-tools: azure-ai-agentserver-responses exited with error 1: Command '['/mnt/vss/_work/1/s/.venv/azure-ai-agentserver-responses/.venv_apistub/bin/python', '-m', 'apistub', '--pkg-path', '/mnt/vss/_work/1/a/azure-ai-agentserver-responses/azure_ai_agentserver_responses-1.0.0b1-py3-none-any.whl', '--out-path', '/mnt/vss/_work/1/a/azure-ai-agentserver-responses']' returned non-zero exit status 1.
=========================================================================================================
```