Split CLI into subcommands

Closes #197, closes #269, updates #284

Move most CLI features to tag subcommand
Split setup options into install subcommand
Split refresh into separate command
Fix nt tag -p for directories and patterns
Update nt refresh to show number of refreshed images
For nt tag and refresh, check if first-time setup is already done, and run if necessary
Add 3 CLI verbosity levels
Update CLI docs and changelog

pyinat / naturtag