By doing so, users no longer need to set an implicit or explicit size
for AnimatedSprite.
[ChangeLog][QtQuick][AnimatedSprite] AnimatedSprite's implicitWidth and
implicitHeight are now based on frameWidth and frameHeight,
respectively. This means it is no longer necessary to explicitly size
AnimatedSprite.
Task-number: QTBUG-36341
Change-Id: I3eb87e9b1c6bb93b3c667123c345341f34e2eee8
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>