Fix: respect base_url from config file when fetching thread with metadata …

[Jordan Kamm (jhkamm)]

…and/or feedback

Problem

I noticed that the cli was attempting to fetch metadata for a thread from the default langsmith api url when I didn't have the LANGSMITH_ENDPOINT env var set, but I did have a config file setup with a custom base-url.

Fix / What Changed

• I took a peek at the code and noticed that base_url wasn't getting passed to the langsmith Client instantiation when fetching metadata and/or feedback for a thread so I just passed the base_url along down the line
• I also noticed the same was happening for feedback fetched for a thread so I passed the base_url through there as well
• Added tests to verify the base_url gets passed along
• Tested manually in my local env as well