Refactor plugin hotkey and action keyword management

Refactored hotkey management to improve thread safety by replacing `Dictionary` with `ConcurrentDictionary` and introducing a lock for updates. Added new methods for hotkey initialization, validation, and translation updates. Enhanced plugin initialization by integrating hotkey checks and removing redundant calls.

Refactored action keyword management with new methods for adding and removing keywords, ensuring thread safety with `TryAdd`, `AddOrUpdate`, and `TryRemove`. Introduced the `PluginHotkeyChangedEvent` class to encapsulate hotkey change events.

Improved thread safety and performance by using thread-safe collections and LINQ. Cleaned up code by removing deprecated methods, redundant comments, and outdated TODOs. Fixed concurrency issues and ensured consistent updates to plugin metadata and hotkey information.

Author: Jack251970