Set the thermal (on the current layer) of pins or vias to the given style.
Style = 0 means no thermal.
Style = 1 has diagonal fingers with sharp edges.
Style = 2 has horizontal and vertical fingers with sharp edges.
Style = 3 is a solid connection to the plane.
Style = 4 has diagonal fingers with rounded edges.
Style = 5 has horizontal and vertical fingers with rounded edges.