message: support initiallyCollapsed in CustomStructureControls
diff: @@ -264,7 +264,7 @@ export class LociLabels extends PluginUIComponent<{}, { entries: ReadonlyArray<L
  }
  }
  -export class CustomStructureControls extends PluginUIComponent {
  +export class CustomStructureControls extends PluginUIComponent<{ initiallyCollapsed?: boolean }> {
  componentDidMount() {
  this.subscribe(this.plugin.state.behaviors.events.changed, () => this.forceUpdate());
  }
  @@ -272,7 +272,7 @@ export class CustomStructureControls extends PluginUIComponent {
  render() {
  const controls: JSX.Element[] = []
  this.plugin.customStructureControls.forEach((Controls, key) => {
  - controls.push(<Controls key={key} />)
  + controls.push(<Controls initiallyCollapsed={this.props.initiallyCollapsed} key={key} />)
  })
  return controls.length > 0 ? <>{controls}</> : null
  }
  