Enhance context

[AndyOGo]

The first prototype of an asynchronous context implementation works quite good in production.
Though it isn't feature complete.

• Multiple contexts

  class AXAFoo extends BaseComponentGlobal {
    constructor() {
      super();
  
      this.enableContext();
    }
  }
  
  class AXABar extends BaseComponentGlobal {
    constructor() {
      super();
  
      this.enableContext();
    }
  }
  
  class AXABaz extends BaseComponentGlobal {
    constructor() {
      super(stylesSticky, templateSticky);
  
      this.selectContext('axa-foo', 'axa-bar');
    }
  
    connectedCallback() {
      super.connectedCallback();
    }
  
    contextCallback(contextNode) {
      // nodeName ist the context's name/key
      const { nodeName } = contextNode;
    }
  }

• Share contextual Data (not just a contextNode)
• Contextual Lifecycle methods
  • contextConnectedCallback (just a proposed rename of contextCallback)
  • contextChangedCallback
  • contextDisconnectedCallback

[LucaMele]

closing as new plib version is live. If issue is with v2 still relevant, please re-open