fix(share): send item if mouse is inside bar, not center

Previously when center of element was on the bar, that element was sent.
This time when the point that is being dragged by is on the bar, element
is sent.
chore(style): add mix-in for dimensions of objects
chore(style): remove unnecessary class from elements
fix(mirror): reflect changes in wams client

Since all attributes are moved deeper in the object, we need to extract
them from deeper position.
fix(share): send all attributes when element is sent over network

All attributes are sent, they are all deeper in structure