feat: add onScaleEnd, vertexSolidSetter and edgeSolidSetter to options

[CorvusYe]

In onScaleEnd, fix the issue where the onVertexTapUp callback cannot be triggered again when a vertex was dragged.

Dev habit change

• (Compared to 2.1.0) Edge.solid and Vertex.solid default to true, now changed to false, to maintain the habits before 2.1.0.

  （与 2.1.0 相比）Edge.solid 跟 Vertex.solid 默认为 true，为了保持与 2.1.0 之前版本的习惯，现在修改成默认false。

[CorvusYe]

@NoachDev
I changed the default value to false to maintain the original features. ( It's the same in Edge. )
If there are no issues, I will proceed with the merger.

You can refer to persistence_demo

        ..vertexSolidSetter = ((vertex, paint) {
          paint.color = vertex.colors.first;
          return paint;
        })
        ..edgeSolidSetter = ((edge, paint) {
          paint.color = edge.start.colors.lastOrNull ?? Colors.white;
          return paint;
        })

[NoachDev]

Ohhh, your version with setters is much better than my initial idea!

I think the UI props could benefit from better encapsulation, similar to Flutter's container decorations, while still maintaining the granular definition of vertex-by-vertex. I have some new features to propose in a pull request. Could this be a potential suggestion?

[CorvusYe]

This is definitely possible, as it aligns more closely with developers’ established habits. Although I haven’t delved deeply into container decoration, I sense that the mechanism for periodic redrawing of the canvas differs from setState. I wonder if this difference aligns with your perspective.

[NoachDev]

I mentioned the decoration of container because it is a good visualization of a complete separation of design from other resources, and if implemented, it will influence "globally" - all vertices, all edges. But the idea of introducing the Decoration themselves might be possible, similar features developed in /shapes and /options already existing in this class. However, this will be a hard work of refactoring, probably unnecessary.

[CorvusYe]

It does offer greater control over vertex styles.

If you’re interested, go ahead and experiment. The control over vertexes in version 1.x utilized Flame’s ShapeComponent. However, Flame is no longer available. Nevertheless, you might find the concept useful.

Ultimately, the decision is yours. I only mentioned this in passing.

[NoachDev]

Okay, thanks for the better clarification