fix: resolve Windows GBK encoding issue in CLI output

[fanghuaqi]

Summary

Fixes UnicodeEncodeError when running ddgs CLI commands on Windows with GBK console encoding.

Changes

• Set stdout/stderr to UTF-8 encoding in safe_entry_point()
• Fixes UnicodeEncodeError when output contains special Unicode characters (e.g., Arabic characters, Chinese characters, trademark symbols ™)
• Only applies on Windows when sys.stdout.reconfigure() is available
• Add test case for extract command

Problem

On Windows, the default console encoding is GBK. When ddgs CLI outputs results containing characters that can't be encoded in GBK (like Arabic characters, Chinese characters, or special symbols), it crashes with:

UnicodeEncodeError: 'gbk' codec can't encode character 'ع' in position 61: illegal multibyte sequence

Solution

Instead of adding exception handling to every click.secho() call, we set the stdout/stderr encoding to UTF-8 at the program entry point in safe_entry_point(). This is a cleaner, more comprehensive solution that:

1. Fixes the encoding issue for all CLI commands at once
2. Doesn't require modifying individual output functions
3. Falls back gracefully if reconfigure() is not available

if sys.platform == "win32" and hasattr(sys.stdout, "reconfigure"):
    try:
        sys.stdout.reconfigure(encoding="utf-8")
        sys.stderr.reconfigure(encoding="utf-8")
    except Exception:
        pass

Testing

• All 9 CLI tests pass
• Added test_extract_command test case
• Verified with Chinese characters, Arabic characters, and special symbols