rax [BUG] render returns undefined to undefined empty nodes are also rebuilt

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Rax Core

Minimal code and steps to reproduce the bug

import { Component } from 'rax';

class UndefinedDemo extends Component {
  constructor(props) {
    super(props);

    this.state = {
      alwaysUndefined: false,
    };
  }

  render() {
    return (
      <div>
        {this.state.alwaysUndefined ? undefined : undefined}

        <button
          onClick={() => {
            this.setState({
              alwaysUndefined: !this.state.alwaysUndefined
            });
          }}
        >
          Switch
        </button>
      </div>
    )
  }
}

reference: fix: render returns null to null empty nodes are also rebuilt(#1830) #1842

shouldUpdateComponent method should also checkundefined type.