fix(animations): remove inline styles when finished

Allows for one animation to control multiple elements. Optionally
removes inline styles when the animation finishes. Fixes checking for
the will-change property. Does not always apply translateZ on ion-page.

Closes #5130

ionic/components/app/structure.scss

@@ -113,7 +113,6 @@ ion-page {
   left: 0;
   width: 100%;
   height: 100%;
-  transform: translateZ(0);
 
   &.show-page {
     display: flex;