Migrate to Mantine v8 and Design Changes (#961)

* mantine v8 migration

* various design changes and improvements

src/renderer/layouts/default-layout/right-sidebar.module.css

@@ -0,0 +1,15 @@
+.right-sidebar-container {
+    position: relative;
+    grid-area: right-sidebar;
+    height: 100%;
+    border-left: 1px solid alpha(var(--theme-colors-border), 0.3);
+
+    .current-song-cell:not(.current-playlist-song-cell) svg {
+        display: none;
+    }
+}
+
+.queue-drawer {
+    background: var(--theme-colors-background);
+    border-radius: var(--theme-radius-lg);
+}