[BUG] Text components don't behave correctly after creating custom components

Hi artf,

After creating custom components, the text component does not behave like before. It removes all the naked nodes after changing some code in import modal. e.g

<div>Insert your text 
        <a data-cke-saved-href="http://abc" href="http://abc">here</a>
</div>

After editing something in import modal it gets change to:

<div>
        <a data-cke-saved-href="http://abc" href="http://abc">here</a>
</div>

As you can see it removed the Naked text node i.e Insert your text. It should be noted that this behavior doesnt happen when there is no custom component added to the editor.

An example of custom component that i created:

export const NavbarMenu = editor => {
	var defaultType = editor.DomComponents.getType("default");
	var defaultModel = defaultType.model;
	editor.DomComponents.addType('menu-nav', {
		isComponent: el => el.tagName === 'menu-nav',
		model: defaultModel.extend({
			// Extend default properties
			defaults: Object.assign({}, defaultModel.prototype.defaults, {
				tagName: 'menu-nav',
				removable: true,
				copyable: false,
				droppable: false,
                resizable: false,
				editable: false,
				traits: [
                    {
                        type: 'text',
                        name: 'menuName',
                        label: 'Menu Name'
                    }
                ],
				attributes: {
                    'menuName': 'Header Nav'
				},
				propagate: ['removable', 'droppable', 'copyable', 'editable'],
				components: `
<div data-gjs-selectable="false" class="container-fluid bg-menu">
  <div class="row" data-gjs-selectable="false">
    <div class="col-lg-12" data-gjs-selectable="false">
      <div class="main-nav-center" data-gjs-selectable="false">
        <nav id="main-nav" class="prvidr-navbar-menu text-center" data-gjs-selectable="false">
          <ul id="main-menu" class="sm pixelstrap sm-horizontal catch-menu" data-gjs-selectable="false">
            <li data-gjs-selectable="false">
              <a data-gjs-selectable="false" href="javascript:void(0)">
                Menu Item 1
              </a>
            </li>
            <li data-gjs-selectable="false">
              <a data-gjs-selectable="false" href="javascript:void(0)">
                Menu Item 2
              </a>
            </li>
            <li data-gjs-selectable="false">
              <a data-gjs-selectable="false" href="javascript:void(0)">
                Menu Item 3
              </a>
            </li>
            <li data-gjs-selectable="false">
              <a data-gjs-selectable="false" href="javascript:void(0)">
                Menu Item 4
              </a>
            </li>
          </ul>
        </nav>
      </div>
    </div>
  </div>
</div>
				`
			}),
			init(){
				var props = this.getAttributes().props;
				if (props) {
					props = JSON.parse(props);
					this.addAttributes({'menuName':props['menuName']});
				}
			},
			toHTML: function () {
			    let props:any = {};
			    props['menuName'] = this.getAttributes().menuName;
				return `<menu-nav data-gjs-type="menu-nav" props='${JSON.stringify(props)}'></menu-nav>`
			}

		})
	});

	editor.BlockManager.add('menu-nav', {
		label: 'Header Menu',
		attributes: {
			class: 'fa fa-bars'
		},
		category: {
			label: "Dynamic Menu"
		},
		content: {
			type: 'menu-nav'
		}
	});
}