Arvados

19830-pysdk-util-docs @ 65a84ec3801f6b76ccc2e6af07511851b4dc3aba - developer-run-tests: #3917

The type annotations adedd in this branch refer to `arvados.api_resources.ArvadosAPIRequest`. This class is added in the branch for #21132. I have tested and confirmed that pdoc will render these references correctly after #21132 is merged.

While working on that, I had a moment where I thought I was going to need to make some adjustments to `run_test_server.py`. Thankfully I walked away from that ledge. But I did get as far as cleaning the imports, and that's a simple nice change so we might as well keep it. That's included.

• All agreed upon points are implemented / addressed.
  • Yes
• Anything not implemented (discovered or discussed during work) has a follow-up story.
  • N/A
• Code is tested and passing, both automated and manual, what manual testing was done is described
  • Yes, see above
• Documentation has been updated.
  • N/A
• Behaves appropriately at the intended scale (describe intended scale).
  • N/A
• Considered backwards and forwards compatibility issues between client and server.
  • N/A
• Follows our coding standards and GUI style guidelines.
  • Yes

Really nice, LGTM.