Add Heading card (#22008)

* Add header card

* Rename to heading card

* Add heading entities

* Add editor for entities

* Remove unused property

* Fix margin and gap

* Improve content and entities container

* Fix no entities displayed

* Cache form to not loose state

* Use style

* Fix type

* Add support for string entities

* Add tap action support to entities

* Move expandable outside of entities editor

* Fix double processing

src/panels/lovelace/create-element/create-card-element.ts

@@ -10,6 +10,7 @@ import "../cards/hui-sensor-card";
 import "../cards/hui-thermostat-card";
 import "../cards/hui-weather-forecast-card";
 import "../cards/hui-tile-card";
+import "../cards/hui-heading-card";
 import {
   createLovelaceElement,
   getLovelaceElementClass,
@@ -29,6 +30,7 @@ const ALWAYS_LOADED_TYPES = new Set([
   "thermostat",
   "weather-forecast",
   "tile",
+  "heading",
 ]);
 
 const LAZY_LOAD_TYPES = {