Add auto-update notifications and confirmation (#1941)

* add auto-update notifications and confirmation

* Show single update notification (#1985)

* Moving notification icons to top (#1987)

* Switch to EventEmitter (producer&consumer) model

* Add `onCorrect` and `onceCorrect` to ipc module for typechecking ipc  messages

* move type enforced ipc methods to seperate file, add unit tests

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>
Signed-off-by: Alex Andreev <alex.andreev.email@gmail.com>
Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/renderer/components/button/button.scss

@@ -21,10 +21,16 @@
   &.primary {
     background: $buttonPrimaryBackground;
   }
+
   &.accent {
     background: $buttonAccentBackground;
   }
 
+  &.light {
+    background-color: $buttonLightBackground;
+    color: #505050;
+  }
+
   &.plain {
     color: inherit;
     background: transparent;

src/renderer/components/button/button.tsx

@@ -8,6 +8,7 @@ export interface ButtonProps extends ButtonHTMLAttributes<any>, TooltipDecorator
   waiting?: boolean;
   primary?: boolean;
   accent?: boolean;
+  light?: boolean;
   plain?: boolean;
   outlined?: boolean;
   hidden?: boolean;
@@ -24,13 +25,16 @@ export class Button extends React.PureComponent<ButtonProps, {}> {
   private button: HTMLButtonElement;
 
   render() {
-    const { className, waiting, label, primary, accent, plain, hidden, active, big, round, outlined, tooltip, children, ...props } = this.props;
-    const btnProps = props as Partial<ButtonProps>;
+    const {
+      className, waiting, label, primary, accent, plain, hidden, active, big,
+      round, outlined, tooltip, light, children, ...props
+    } = this.props;
+    const btnProps: Partial<ButtonProps> = props;
 
     if (hidden) return null;
 
     btnProps.className = cssNames("Button", className, {
-      waiting, primary, accent, plain, active, big, round, outlined
+      waiting, primary, accent, plain, active, big, round, outlined, light,
     });
 
     const btnContent: ReactNode = (