feat(views/board): set up scroll via mouse wheel

apps/client/src/widgets/widget_utils.ts

@@ -0,0 +1,18 @@
+import utils from "../services/utils.js";
+
+/**
+ * Enables scrolling of a container horizontally using the mouse wheel, instead of having to use the scrollbar or keep Shift pressed.
+ *
+ * @param $container the jQuery-wrapped container element to enable horizontal scrolling for.
+ */
+export function setupHorizontalScrollViaWheel($container: JQuery<HTMLElement>) {
+    $container.on("wheel", (event) => {
+        const wheelEvent = event.originalEvent as WheelEvent;
+        if (utils.isCtrlKey(event) || event.altKey || event.shiftKey) {
+            return;
+        }
+        event.preventDefault();
+        event.stopImmediatePropagation();
+        event.currentTarget.scrollLeft += wheelEvent.deltaY + wheelEvent.deltaX;
+    });
+}