Closes #629.

🚧 WIP: This is probably the most significant refactoring of the entire project.

This PR introduces 6 reporters:

• poku (default):
  • logs all describe, it, test and assert titles and messages, including their modifiers.
  • logs only the file name for errors during the execution, then lists all logs for each failed file at the running end.
• dot (inspired by Mocha):
  • logs a dot for each success file test and F for each failed file.
  • lists all logs for each failed file at the running end.
• compact (inspired by modern Tap):
  • lists only file paths with PASS or FAIL and, in case of failures, lists all logs for each failed file at the running end.
• focus:
  • Logs only errors (in real time). If there is no error, it just logs a small footnote resume.
• verbose:
  • just like the default (poku), but logs errors in real time and also at the running end.
• classic:
  • The standard report style from version 2 to preserve our history 🐷

⏳ Progress:

• CLI
• API
• Config File