feat：Toast 新增 remove、removeAll 回调

[HuXin957]

First of all, thank you for your contribution! :-)

Please makes sure that these checkboxes are checked before submitting your PR, thank you!

• [ ] Make sure that you follow antd's code convention.
• [ ] Run npm run lint and fix those errors before submitting in order to keep consistent code style.
• [ ] Rebase before creating a PR to keep commit history clear.
• [ ] Add some descriptions and refer relative issues for you PR.

Extra checklist:

if isBugFix :

• [ ] Make sure that you add at least one unit test for the bug which you had fixed.

elif isNewFeature :

• [ ] Update API docs for the component.
• [ ] Update/Add demo to demonstrate new feature.
• [ ] Update TypeScript definition for the component.
• [ ] Add unit tests for the feature.

[1uokun]

针对 issue https://github.com/ant-design/ant-design-mobile-rn/issues/1195 提出的

// 在调用Toast.removeAll()时能正常输出 “hello”
Toast.loading('xx',0,()=>console.log('hello'))
Toast.removeAll()

在本次的mr中并没有实现哦

[HuXin957]

针对 issue #1195 提出的

// 在调用Toast.removeAll()时能正常输出 “hello”
Toast.loading('xx',0,()=>console.log('hello'))
Toast.removeAll()

在本次的mr中并没有实现哦

这只是个设想。如果将回调放到打开loading的方法中，那只能固定时间后执行，在异步中是不符合需求的。所以只能将回调放到关闭loding的方法中。所以最终是我给removeAll、remove加了一个回调

[1uokun]

那和

Toast.removeAll();
callback();

没什么区别呢

[erichua23]

针对 issue #1195 提出的

// 在调用Toast.removeAll()时能正常输出 “hello”
Toast.loading('xx',0,()=>console.log('hello'))
Toast.removeAll()

在本次的mr中并没有实现哦

如果只是实现这个功能，componentWillUnmount里面处理一下就行了。有动画的onClose依赖于动画结束的回调，duration为0的就直接单独根据 WillUnmount 来判断。

或者更精简的，可以把

    this.anim.start(() => {
      if (duration > 0) {
        this.anim = null
        if (onClose) {
          onClose()
        }
        if (onAnimationEnd) {
          onAnimationEnd()
        }
      }
    })

这里面的onClose回调都不要了，都走componentWillUnmount来触发就好了，效果是一样的，代码流程简单很多。 @1uokun 看看，这个思路没问题的话，我提个PR。