Add tool for removing tape

[MarcelGarus]

Let's be real. If developers realize that tape is not the right tool for the job, we want to support them too. It would be great if there was a tapegen remove command (or something similar) that

• removes all tape annotations from all classes
• removes the tape.dart file
• removes the initializeTape() call from main
• removes imports of package:tape/tape.dart
• removes tape from dependencies as well as taped-packages
• removes tapegen from dev_dependencies
• if there's no other dev dependency apart from build_runner, remove that too.