feat: new welcome modal, refactor many things, various bug fixes, use material-ui v5 etc

Co-authored-by: Alex Sparkes <turbomarshmello@gmail.com>

src/components/widgets/time/Clock.jsx

@@ -111,6 +111,10 @@ export default class Clock extends React.PureComponent {
     this.startTime(0);
   }
 
+  componentWillUnmount() {
+    EventBus.remove('refresh');
+  }
+
   render() {
     let clockHTML = <h1 className='clock clock-container'>{this.state.time}<span className='ampm'>{this.state.ampm}</span></h1>;