Use mp3 audio instead of wav

wav needs ffmpeg which vscode does not ship with, mp3 is best for compat

Author: Tyriar

src/common/services/OptionsService.ts

@@ -12,7 +12,7 @@ import { clone } from 'common/Clone';
 // This sound is released under the Creative Commons Attribution 3.0 Unported
 // (CC BY 3.0) license. It was created by 'altemark'. No modifications have been
 // made, apart from the conversion to base64.
-export const DEFAULT_BELL_SOUND = 'data:audio/wav;base64,UklGRigBAABXQVZFZm10IBAAAAABAAEARKwAAIhYAQACABAAZGF0YQQBAADpAFgCwAMlBZoG/wdmCcoKRAypDQ8PbRDBEQQTOxRtFYcWlBePGIUZXhoiG88bcBz7HHIdzh0WHlMeZx51HmkeUx4WHs8dah0AHXwc3hs9G4saxRnyGBIYGBcQFv8U4RPAEoYRQBACD70NWwwHC6gJOwjWBloF7gOBAhABkf8b/qv8R/ve+Xf4Ife79W/0JfPZ8Z/wde9N7ijtE+wU6xvqM+lb6H7nw+YX5mrlxuQz5Mzje+Ma49fioeKD4nXiYeJy4pHitOL04j/jn+MN5IPkFOWs5U3mDefM55/ogOl36m7rdOyE7abuyu8D8Unyj/Pg9D/2qfcb+Yn6/vuK/Qj/lAAlAg==';
+export const DEFAULT_BELL_SOUND = 'data:audio/mp3;base64,SUQzBAAAAAAAI1RTU0UAAAAPAAADTGF2ZjU4LjMyLjEwNAAAAAAAAAAAAAAA//tQxAADB8AhSmxhIIEVCSiJrDCQBTcu3UrAIwUdkRgQbFAZC1CQEwTJ9mjRvBA4UOLD8nKVOWfh+UlK3z/177OXrfOdKl7pyn3Xf//WreyTRUoAWgBgkOAGbZHBgG1OF6zM82DWbZaUmMBptgQhGjsyYqc9ae9XFz280948NMBWInljyzsNRFLPWdnZGWrddDsjK1unuSrVN9jJsK8KuQtQCtMBjCEtImISdNKJOopIpBFpNSMbIHCSRpRR5iakjTiyzLhchUUBwCgyKiweBv/7UsQbg8isVNoMPMjAAAA0gAAABEVFGmgqK////9bP/6XCykxBTUUzLjEwMKqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq';
 
 // TODO: Freeze?
 export const DEFAULT_OPTIONS: ITerminalOptions = Object.freeze({