Migrate to Mantine v8 and Design Changes (#961)

* mantine v8 migration

* various design changes and improvements

src/shared/components/separator/separator.tsx

@@ -0,0 +1,5 @@
+import { SEPARATOR_STRING } from '/@/shared/api/utils';
+
+export const Separator = () => {
+    return <>{SEPARATOR_STRING}</>;
+};