[ADF-4867] adf-error-component refactor (#5056)

* Refactor the adf-error-component
Move the custom buttons on demoshell
Fix unit test
Remove usefull e2e

* Add basic example

docs/core/components/error-content.component.md

@@ -24,8 +24,6 @@ this.router.navigate(['/error', errorCode]);
 | Name | Type | Default value | Description |
 | ---- | ---- | ------------- | ----------- |
 | errorCode | `string` |  | Error code associated with this error. |
-| returnButtonUrl | `string` | "/" | Target URL for the return button. |
-| secondaryButtonUrl | `string` | "report-issue" | Target URL for the secondary button. |
 
 ## Details
 
@@ -49,6 +47,20 @@ You can customize your error messages by adding them to the translate files insi
   }
 ```
 
+## How to customise the action button.
+
+The errorContentComponent allows you to customise the actions section using the selector `adf-error-content-actions`. 
+
+For example you can have a custom action button with the following code
+
+```html
+<adf-error-content [errorCode]="errorCode">
+    <div adf-error-content-actions>
+       <button type="button">MyAction</button>
+    </div>
+</adf-error-content>
+```
+
 ## See also
 
 -   [Empty Content component](empty-content.component.md)