Tweak logging to improve UX

[antonymilne]

The milestone Improve the setup of logging is complete! However, there are still a couple of minor issues we should try to resolve before 0.19.

• Make framework-side logging.yml user-specifiable #2206
• Introduce our own rich console logging handler #2277
• Remove logs folder #2429
• Make rich markup compatible with file-based logs #2207
• Consider removing support for project-side logging.yml #2281
• Work out to show DEBUG level messages emitted early in kedro process #2208
• Follow up tickets on project-side logging user research #2383
• Divorce config loader from logging.yml #2426
• Make sure project logs of INFO level are shown #2520
• Consider whether we should introduce a .env file to setup logging #2428

Reminder about how logging works:

1. LOGGING = _ProjectLogging() is called to set up the framework-side logging configuration given in default_logging.yml
2. configure_project called by bootstrap_project imports settings.py (so users can currently "unofficially" insert code there e.g. to disable rich tracebacks)
3. session is created, and project-side logging.yml loads (if it exists) by session._setup_logging
4. if operating parallel runner with spawned subprocess, configure_logging is called in each subprocess by _bootstrap_subprocess

[merelcht]

All tasks have now been completed.