Port AutoLine over to new framework

[ejnnr]

This PR replaces #10 (though it doesn't have all the same features yet).

Example usage that works:

box_a = ice.Rectangle(ice.Bounds(0, 0, size=(50, 50)), border_color=ice.Colors.BLACK)
box_b = ice.Rectangle(
    ice.Bounds(200, 400, size=(50, 50)), border_color=ice.Colors.BLACK
)
line = ice.AutoLine(
    box_a,
    box_b,
    directions="rdrdl",
    path_style=ice.PathStyle(color=ice.Colors.RED),
    x_padding=20,
    corner_radius=10,
)
scene = ice.Compose(box_a, box_b, line)

Animation example that doesn't work yet:

class Animation(ice.Playbook):
    def timeline(self):
        box_a = ice.Rectangle(
            ice.Bounds(0, 0, size=(50, 50)), border_color=ice.Colors.BLACK
        )
        box_b = ice.Rectangle(
            ice.Bounds(200, 400, size=(50, 50)), border_color=ice.Colors.BLACK
        )

        directions = ["rdrdl", "rurdl"]
        lines = [
            ice.AutoLine(
                box_a,
                box_b,
                directions=d,
                path_style=ice.PathStyle(color=ice.Colors.RED),
                x_padding=20,
                y_padding=20,
                corner_radius=10,
            )
            for d in directions
        ]

        line = ice.Animated(lines, 1.0)

        scene = (
            ice.Compose(box_a, box_b, line)
            .pad(20)
            .background(ice.Colors.WHITE)
            .scale(2)
        )
        self.play(scene)


Animation().ipython_display(display_format="gif")

(just jumps suddenly)