QHoverEvent::scenePosition() is actually local position

QHoverEvent in Qt 5 did not provide scene position at all: only pos() and oldPos() (and the floating-point versions). But now that it inherits QSinglePointEvent, it has more accessors (also a QEventPoint), so it's reasonable for users to notice that this extra info is available and then be disappointed that it's not correct. Found while writing an autotest for QTBUG-92563