Fix issue #17: Dynamic color mapping for "fail-on" messages/categories in ColorizedTextReporter

[snipr-ben]

This pull request fixes #17.

The issue has been successfully resolved. The PR made the following key changes:

1. Modified the ColorizedTextReporter to accept a linter instance in its constructor and dynamically update color mapping based on the linter's fail_on_symbols attribute.

2. Added a new method _update_color_mapping that applies the same styling (red + bold) to custom fail-on symbols as used for error messages.

3. Updated the reporter registration to pass the linter instance to the ColorizedTextReporter.

These changes ensure that:

• Custom fail-on messages will now be displayed with the same visual prominence as error messages (red + bold)
• The solution works with any custom fail-on configuration
• The implementation maintains backward compatibility
• The coloring is applied consistently regardless of whether the fail-on symbols are default or custom

The solution directly addresses the original issue by making custom fail-on messages stand out in CI logs, eliminating the need for manual workarounds. The implementation provides the dynamic behavior requested in the original issue description.