Extend PR #6: Improve clip update event structure and state tracking

[dazzatronus]

Overview

This PR builds upon the work started in #6 by @ferozhussain, implementing a more robust event system for clip state management.

Reference

• Original PR: Trigger clip:selected event on resize completion #6
• Relevant discussion: #6 (comment)

Changes

• Clearly separated clip selection and state update events for better responsibility boundaries.
• Introduced a clip:updated event that provides both previous and current state data in a structured format.
• Implemented precise change detection to ensure update events are only emitted on meaningful state changes.
• Preserved backwards compatibility with existing event handlers.

Benefits

• More predictable and maintainable event behaviour, following industry best practices.
• Eliminates reference-related bugs by providing deep copies of state for comparison.
• Enables easier debugging and more reliable state management for consumers of the event system.