[+] Add 'hatching' shading

[+] Add postEffect.edge

[^] Improve lines3D.

• [+] Add polyline property. Support polyline coords for better track visualization.

• [+] Add effect.constantSpeed property

• [^] Improve trail effect

[^] Improve bar3D layout. See https://github.com/ecomfe/echarts-gl/issues/53

[^] bar3D, scatter3D support highlight and downplay from visualMap. See https://github.com/ecomfe/echarts-gl/issues/54