feat(Slideover): preset support (#68)

Co-authored-by: Benjamin Canac <canacb1@gmail.com>

src/runtime/components/overlays/Modal.vue

@@ -12,7 +12,7 @@
           leave-from="opacity-100"
           leave-to="opacity-0"
         >
-          <div class="fixed inset-0 bg-gray-500/75 dark:bg-gray-600/75 transition-opacity" />
+          <div class="fixed inset-0 transition-opacity" :class="overlayClass" />
         </TransitionChild>
 
         <div class="fixed inset-0 overflow-y-auto">
@@ -77,6 +77,10 @@ const props = defineProps({
     type: String,
     default: () => $ui.modal.background
   },
+  overlayClass: {
+    type: String,
+    default: () => $ui.modal.overlay
+  },
   shadowClass: {
     type: String,
     default: () => $ui.modal.shadow