Further menu layout optimizations

* Add dropdown menu shadow
* Move up triangle by 1px

Issue-Ref: 4006
Issue-Url: https://af3-developer.fortiss.org/issues/4006



Signed-off-by: Simon Barner <barner@fortiss.org>

org.fortiss.af3.rcp.help/html/requirements/stylesheet.css

@@ -194,7 +194,7 @@ h4 {
   position: absolute;
   background-color: white;
   min-width: 300px;
-  box-shadow: white;
+  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
   z-index: 1;
 }
 
@@ -300,7 +300,7 @@ label.hamburger {
 
 .triangle {
     position: absolute; 
-    top: 22px;
+    top: 21px;
     width: 0; 
     height: 0; 
     margin-left: 6px;