Allow GRID and LINE snapping when drawing shapes

Is your feature request related to a problem? Please describe.
Can't create shapes like lines (e.g. when drawline is enabled in the modebar) at EXACT positions on the grid or at other lines points

Describe the solution you'd like
Allow the user to enable grid and / or line snapping when drawing shapes

Describe alternatives you've considered
None

Additional context
These guys have it: https://pattycake.io/new/drawing

该 issue 未指定文件或测试；首先定位在 modebar 中启用 drawline 时使用的形状绘制路径，然后跟踪网格和其他线点的表示方式。完成标准是，用户可以在绘制形状时启用网格和/或线捕捉，并在精确位置创建线条或其他形状，同时为新行为提供覆盖。