Add scoped & color coded logging

[joe-replin]

Subject

Add a new way for plugins to log messages with their name automatically included, and introduce a SUCCESS log level for highlighting positive outcomes.

Description

I've been doing this on my projects while debugging/troubleshooting and think it would be helpful for others.

1. Scoped loggers - Allow plugins to create a logger that automatically prefixes all messages with the plugin name
2. SUCCESS log level - A new log level to show positive outcomes

This makes console output much easier to read when multiple plugins are running, especially during development and debugging.