v0.8.4, build 167

Added the possibility to provide default options for the icon finder assistant
Improved switch component for settings: when an option is enabled, the switch is using a different color
Fixed the applying of spellchecking settings to the single-line dialog
Restructured the layout of the settings page
Refactored the settings data model
Upgraded to Rust 1.80.0
Upgraded all Rust dependencies