Develop - Disconnected toast and widget transparency

[sameerasw]

This pull request introduces a new user-configurable widget transparency setting, allowing users to adjust the transparency of the AirSync widget background via the app's settings. It also improves user feedback for connection issues by displaying more informative toast messages. The main changes are grouped below:

Widget Transparency Feature:

• Added a new widgetTransparency float preference to DataStoreManager, along with getter and setter methods to persist and retrieve the value. [1] [2]
• Updated the repository (AirSyncRepository and AirSyncRepositoryImpl) to expose methods for setting and getting widget transparency. [1] [2]
• Extended the UiState data class and AirSyncViewModel to track and update widget transparency, including observing changes and syncing them to the widget. [1] [2] [3]
• Added a new ConfigSliderItem composable for adjustable slider controls, and integrated it into the Settings screen under a new "Widget" section for transparency adjustment. [1] [2]
• Modified AirSyncWidgetProvider to apply the user-selected transparency to the widget background using the stored alpha value.
• Added new vector drawables for the slider increment/decrement buttons. [1] [2]

User Feedback Improvements:

• Enhanced WebSocketUtil to show more descriptive toast messages to users on disconnection and connection failures, helping users better understand connection issues. [1] [2]

These changes collectively improve the widget's customization options and the overall user experience regarding connection feedback.