[Fix] No scroll outside when in menu (#116)

Author: imengyu

library/ContextMenu.scss

@@ -66,12 +66,7 @@
   overflow: visible;
 }
 .mx-context-menu-scroll {
-  position: absolute;
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 1px;
-  pointer-events: none;
+  overscroll-behavior: contain;
 }
 
 //Item
@@ -82,6 +77,7 @@
   align-items: center;
   position: relative;
   padding: 6px 15px;
+  -webkit-user-select: none;
   user-select: none;
   overflow: visible;
   white-space: nowrap;

library/ContextSubMenu.vue

@@ -26,6 +26,7 @@
           width: 'auto',
           height: `${overflow ? maxHeight : scrollHeight}px`,
         }"
+        containerClass="mx-context-menu-scroll"
       >
         <!--Child menu items-->
         <div