[Update] Add Starting Up Animation and downloading models progress display.

Backend: Move the init progressed position 4 to a little bit earlier.

src-ui/app/splash_component/download_models_container/DownloadModelsContainer.module.scss

@@ -0,0 +1,63 @@
+.container {
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    overflow: hidden;
+    background-color: var(--dark_888_color);
+}
+
+.progress_container {
+    position: absolute;
+    top: 77%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    width: 90%;
+    gap: 6px;
+    display: flex;
+    flex-direction: column;
+}
+
+.labels_wrapper {
+    position: relative;
+    width: 100%;
+    height: 100%;
+}
+
+.logo_img {
+    position: absolute;
+    top: 42%;
+    left: 50%;
+    width: 280px;
+    transform: translate(-50%, -50%);
+}
+.vrct_now_downloading_img {
+    position: absolute;
+    bottom: 2px;
+    right: 10px;
+    width: 300px;
+}
+
+.progress_bar_container {
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+    justify-content: center;
+}
+
+.progress_bar_wrapper {
+    background-color: var(--dark_800_color);
+}
+
+$progress_ease: cubic-bezier(0, 1, 0.75, 1);
+.progress_bar {
+    height: 8px;
+    transition: width 0.3s $progress_ease;
+}
+
+.progress_label {
+    text-align: end;
+    font-size: 12px;
+    color: var(--dark_400_color);
+}