Filter response keys before printing result

[virtualzx-nad]

Original issue: httpie#1550

Problem:
Users need the ability to filter specific keys from the response before it's printed to the screen.

Requirements:

1. Add new command line option for key filtering
2. Support both inclusion and exclusion filters
3. Handle nested JSON structures
4. Add support for wildcard patterns
5. Include tests
6. Update documentation

Difficulty: Beginner-friendly
Type: Enhancement