Feature: #103576 - Allow defining opacity in TCA type=color element

Description

A new boolean property opacity has been added to the TCA configuration of a TCA type color element to allow defining colors with an opacity using the RRGGBBAA color notation.

'my_color' => [
    'label' => 'My Color',
    'config' => [
        'type' => 'color',
        'opacity' => true,
    ],
],

Impact

If opacity is enabled, editors can select not only a color but also its opacity in a corresponding color element.