Slack indexing: add name to each user contributing to a thread

[danielnaber]

Description

danswer misattributed facts from threads in Slack in my tests (i.e. claimed that X said something when it was actually someone else from the thread who said it). Adding the author's name seems to help with that.

I also changed the __main__ part to be more useful for testing -> print all docs, not just the first one.

How Has This Been Tested?

Manually tested results with a few cases. Indexing works with a large Slack instance with >50K docs indexed.

Accepted Risk

I'm not aware of any risks (but I'm not very experienced with writing connectors).

Checklist:

• All of the automated tests pass
• All PR comments are addressed and marked resolved
• If there are migrations, they have been rebased to latest main
• If there are new dependencies, they are added to the requirements
• If there are new environment variables, they are added to all of the deployment methods
• If there are new APIs that don't require auth, they are added to PUBLIC_ENDPOINT_SPECS
• Docker images build and basic functionalities work
• Author has done a final read through of the PR right before merge

[vercel]

@danielnaber is attempting to deploy a commit to the Danswer Team on Vercel.

A member of the Team first needs to authorize it.