Implement fs copy from HTTP

[maddenp-noaa]

Description

Extend fs copy mode/action to get files over HTTP.

AC

• Uses the requests library for data transfer.
• Uses urllib.parse to get protocol from URL.
• No protocol (as before) or file:// => local filesystem.
• Attempts to use http:// or https:// in a destination path fail with an informative error message.
• Unit tests are added.
• Documentation is updated with one or more examples.
• Both CLI and API access is provided.