Implemented new flags to filter and match HTTP responses based on Content-Type header:
- -mct: Match responses with specific Content-Type (show only these)
- -fct: Filter responses with specific Content-Type (hide these)

Features:
- Exact match: application/json, text/plain, text/html
- Wildcard support: application/*, text/*, image/*
- Substring match: json, xml, plain
- 'all' keyword: matches any content-type
- Comma-separated list support for multiple values
- Automatic charset parameter stripping (e.g., '; charset=utf-8')
- Case-insensitive matching

Interactive mode support:
- fct [value]: Set content-type filter
- afct [value]: Append to content-type filter