Take padding into account when calculating lineheight

The helper function getLineHeight calculates the height of a
contextmenu entry by mocking two entries and divide the height
of the container by two.
But this does not take the padding of the container into account.
Padding must be substracted from the offsetHeight.

src/helpers/dom.ts

@@ -34,7 +34,11 @@ export function getLineHeight(container: HTMLDivElement): number {
     cloned.append(element2);
     container.parentNode?.append(cloned);
 
-    const height = cloned.offsetHeight / 2;
+    const clonedStyle = window.getComputedStyle(cloned);
+    const paddingTop = Number.parseInt(clonedStyle.paddingTop, 10);
+    const paddingBottom = Number.parseInt(clonedStyle.paddingBottom, 10);
+
+    const height = (cloned.offsetHeight - (paddingTop + paddingBottom)) / 2;
 
     container.parentNode?.removeChild(cloned);