[4.x]: craft generator - generated element action class contains errors

[piotrpog]

What happened?

Description

New element action class generated by class generaor contains errors:

• getTriggerHtml() method return value type is set to ?string, yet this method does not return anything. This makes Craft throw exception when we register this action class.
• JS syntaxt error:

validateSelection: (selectedItems) {
  return true;
},

Craft CMS version

4.5.11.1

PHP version

No response

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

[i-just]

Hi, thanks for reporting! Looks like someone already raised a PR for both of your points: #30