Fix insert button distance from cards box

Now that cards boxes no longer has margin, we need to ensure it does
not come to close if content does not span section

REDMINE-21191

Author: tf

entry_types/scrolled/package/src/frontend/inlineEditing/ContentElementInsertButton.module.css

@@ -17,7 +17,8 @@
   border-top: solid 1px currentColor;
   width: calc(50% - 20px);
   position: absolute;
-  top: 0;
+  top: calc(space(1.5) - 1px);
+  z-index: -1;
 }
 
 .container::before {
@@ -37,4 +38,8 @@
   left: 0;
   width: 100%;
   height: space(8);
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  padding-top: space(3)
 }

entry_types/scrolled/package/src/frontend/inlineEditing/SectionDecorator.js

@@ -80,7 +80,9 @@ export function SectionDecorator({backdrop, section, contentElements, transition
                                      position: 'after'})}
       </div>
       <MotifAreaVisibilityProvider visible={isSelected}>
-        <ForcePaddingContext.Provider value={isLastContentElementSelected || isSectionSelected}>
+        <ForcePaddingContext.Provider value={isLastContentElementSelected ||
+                                             isSectionSelected ||
+                                             isHighlighted}>
           {children}
         </ForcePaddingContext.Provider>
       </MotifAreaVisibilityProvider>