feat(popover): sort keymaps and macros alphabetically (#534)

* feat(popover): sort keymaps and macros alphabetically

Closes #512

* small performance refactoring

packages/uhk-web/src/app/util/find-new-item.ts

@@ -0,0 +1,9 @@
+export function findNewItem<T>(oldItems: T[], newItems: T[]): T {
+    for (let i = 0; i < oldItems.length; ++i) {
+        if (oldItems[i] !== newItems[i]) {
+            return newItems[i];
+        }
+    }
+
+    return newItems[newItems.length - 1];
+}

packages/uhk-web/src/app/util/index.ts

@@ -1,3 +1,4 @@
+export * from './find-new-item';
 export * from './html-helper';
 export * from './validators';
 export * from './version-helper';