fix: Safari 12 rendering issue

A CSS animation used to detect element rendering (by triggering an animation event) was triggering a weird rendering bug in Safari 12 where elements would sometimes be shown in wildly incorrect positions. This is now fixed.

Fixes #110

src/vaadin-form-layout.html

@@ -24,7 +24,7 @@
 
       @keyframes vaadin-form-layout-appear {
         to {
-          opacity: 1;
+          opacity: 1 !important; /* stylelint-disable-line keyframe-declaration-no-important */
         }
       }