style: animate structure toggle in profile

src/app/profile/profile-structure/profile-structure.component.scss

@@ -8,6 +8,7 @@
   border: 1px solid $grey-5;
   border-radius: 4px;
   overflow: hidden;
+  transition: all 0.3s;
   &.fold {
     background-color: $grey-8;
     border: 1px solid $grey-8;