Verbose errors

Hey,
I've been struggling with getting pkl to work at work and it turns out from someone else's issue that this is due to the fact pkl doesn't currently support proxies. It is quite diffucult to diagnose what is the problem however with the errors provided, had personally thought it could be cert validation, would it be possible to add a -v or -vvvv like in ansible that generates more verbose logging as to what has gone wrong (not just for the above case but for all commands in pkl)

Start by reproducing the proxy-related failure described in the issue and inspect the current errors produced by pkl commands. The work is complete when commands provide a verbose mode with useful diagnostics for failures, including proxy-related problems.

Written by the indexing model from the issue text.