Clean up media module logic and code. (#380)

* Organized media menu code

* More consolidation

modules/menus/media/components/controls/previous/index.ts

@@ -0,0 +1,27 @@
+const media = await Service.import('mpris');
+import icons from 'lib/icons';
+import { Attribute } from 'lib/types/widget';
+import { getPlayerInfo } from '../../helpers';
+import Button from 'types/widgets/button';
+import Icon from 'types/widgets/icon';
+
+export const previousTrack = (): Button<Icon<Attribute>, Attribute> => {
+    return Widget.Button({
+        hpack: 'center',
+        child: Widget.Icon(icons.mpris.prev),
+        setup: (self) => {
+            self.hook(media, () => {
+                const foundPlayer = getPlayerInfo();
+                if (foundPlayer === undefined) {
+                    self.class_name = 'media-indicator-control-button prev disabled';
+                    return;
+                }
+
+                self.on_primary_click = (): void => {
+                    foundPlayer.previous();
+                };
+                self.class_name = `media-indicator-control-button prev ${foundPlayer.can_go_prev !== null && foundPlayer.can_go_prev ? 'enabled' : 'disabled'}`;
+            });
+        },
+    });
+};