message: ts: add prevStates property in Element
diff: @@ -357,6 +357,8 @@ class Element<Props extends ElementProps = ElementProps> {
  anid: string
  currentStates?: string[] = []
  + // prevStates is for storager in echarts.
  + prevStates?: string[]
  /**
  * Store of element state.
  * '__normal__' key is preserved for default properties.
  