feat: Add Mirai colored box parser

[divyanshub024]

Description

This pull request introduces a new parser for MiraiColoredBox in the mirai package. The most important changes include adding the parser to the framework, defining the MiraiColoredBox class, and updating the necessary files to integrate this new parser.

New parser addition:

• packages/mirai/lib/src/framework/mirai.dart: Added MiraiColoredBoxParser to the list of parsers.

Definition and serialization:

• packages/mirai/lib/src/parsers/mirai_colored_box/mirai_colored_box.dart: Defined the MiraiColoredBox class with freezed and json_serializable support.
• packages/mirai/lib/src/parsers/mirai_colored_box/mirai_colored_box.freezed.dart: Generated code for the MiraiColoredBox class using freezed.
• packages/mirai/lib/src/parsers/mirai_colored_box/mirai_colored_box.g.dart: Generated JSON serialization code for the MiraiColoredBox class.

Integration:

• packages/mirai/lib/src/parsers/mirai_colored_box/mirai_colored_box_parser.dart: Implemented the MiraiColoredBoxParser class to parse MiraiColoredBox widgets.
• packages/mirai/lib/src/parsers/parsers.dart: Exported the mirai_colored_box.dart file.
• packages/mirai/lib/src/utils/widget_type.dart: Added coloredBox to the WidgetType enum.

Closes #9

Type of Change

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Code refactor
• Build configuration change
• Documentation
• Chore