feat: recover scrolled position after Library re-opening (#6624)

Co-authored-by: dwelle <luzar.david@gmail.com>

src/components/LibraryUnit.scss

@@ -20,6 +20,27 @@
       border-color: var(--color-primary);
       border-width: 1px;
     }
+
+    &--skeleton {
+      opacity: 0.5;
+      background: linear-gradient(
+        -45deg,
+        var(--color-gray-10),
+        var(--color-gray-20),
+        var(--color-gray-10)
+      );
+      background-size: 200% 200%;
+      animation: library-unit__skeleton-opacity-animation 0.3s linear;
+    }
+  }
+
+  &.theme--dark .library-unit--skeleton {
+    background-image: linear-gradient(
+      -45deg,
+      var(--color-gray-100),
+      var(--color-gray-80),
+      var(--color-gray-100)
+    );
   }
 
   .library-unit__dragger {
@@ -142,4 +163,18 @@
       transform: scale(0.85);
     }
   }
+
+  @keyframes library-unit__skeleton-opacity-animation {
+    0% {
+      opacity: 0;
+    }
+
+    75% {
+      opacity: 0;
+    }
+
+    100% {
+      opacity: 0.5;
+    }
+  }
 }