Add long --verbose/--quiet cli arguments

[The-Compiler]

As those are pretty common across different projects I'd say.

Will add tests/changelog (?) if this sounds like a good idea.

Contribution checklist:

(also see CONTRIBUTING.rst for details)

• wrote descriptive pull request text
• added/updated test(s)
• updated/extended the documentation
• added relevant issue keyword
  in message body
• added news fragment in changelog folder
  • fragment name: <issue number>.<type>.rst for example (588.bugfix.rst)
  • <type> is must be one of bugfix, feature, deprecation,breaking, doc, misc
  • if PR has no issue: consider creating one first or change it to the PR number after creating the PR
  • "sign" fragment with "by :user:<your username>"
  • please use full sentences with correct case and punctuation, for example: "Fix issue with non-ascii contents in doctest text files - by :user:superuser."
  • also see examples
• added yourself to CONTRIBUTORS (preserving alphabetical order)

[asottile]

probably don't have to bother with tests, though a changelog entry would be good -- thanks!

[The-Compiler]

Done! 🐱 🙌

Also added tests because modifying the existing ones was trivial, and simplified test_verbose a bit while I was at it.

edit: And added myself to CONTRIBUTORS which I apparently never did!