Debug USGS archivers

[e-belfer]

Overview

Closes #654, #722, #684

What problem does this address?

• Handle new version of USGS data
• Handle can't connect errors

What did you change in this PR?

• Move archivers to USGS folder
• Grab links from USGSUSPVDB pages more flexibly to handle new version
• Add user agent
• Add certifi to handle specify certificate location
• Drop the simultaneous number of connections to a source

Testing

How did you make sure this worked? How can a reviewer verify this?

To-do list

• This works locally, but not consistently on the runner! Still more debugging to do here!
• Update relevant documentation - like comments, docstrings, README, release notes, etc.
• Review the PR yourself and call out any questions or issues you have