Description

Fixes issues with repeatable and sortable group with repeatable fields while shifting group. Fixes #1426

Testing procedure

1. Add a bunch of field types (preferably all of them?) to the a group field.

   1. Make sure some of them are set to be repeatable.
   2. e.g.:

   add_action( 'cmb2_admin_init', function() {
   
   	$cmb = new_cmb2_box([
   		'id'            => 'metabox_attachment',
   		'title'         => 'Poo poo',
   		'object_types'  => [ 'page' ], // Post type
   		'priority'      => 'high',
   		'show_names'    => true
   	] );
   
   	$group_field_id = $cmb->add_field( array(
   		'before_group' => function( $args, $field ) {
   			echo '<xmp>'. __LINE__ .') $field->value: '. print_r( $field->value, true ) .'</xmp>';
   		},
   		'id'          => 'wiki_test_repeat_group_1429',
   		'type'        => 'group',
   		'description' => __( 'Generates reusable form entries', 'cmb2' ),
   		'repeatable'  => true,
   		'options'     => array(
   			'group_title'   => __( 'Entry {#}', 'cmb2' ),
   			'add_button'    => __( 'Add Another Entry', 'cmb2' ),
   			'remove_button' => __( 'Remove Entry', 'cmb2' ),
   			'sortable'      => true,
   		),
   	) );
   
   	$cmb->add_group_field( $group_field_id, array(
   			'name' => 'Entry Title',
   			'id'   => 'subtitle',
   			'type' => 'text',
   			'repeatable' => true,
   	) );
   
   	$cmb->add_group_field( $group_field_id, array(
   		'name'       => 'Test Image',
   		'desc'       => 'Upload an image or enter a URL.',
   		'id'         => 'demo_image',
   		'type'       => 'file',
   		'preview_size'    => array( 50, 50 ),
   	) );
   	$cmb->add_group_field( $group_field_id, array(
   		'name'         => 'Multiple Files',
   		'desc'         => 'Upload or add multiple images/attachments.',
   		'id'           => 'demo_file_list',
   		'type'         => 'file_list',
   	) );
   
   	$cmb->add_group_field( $group_field_id, array(
   		'name'    => 'Color',
   		'id'      => 'demo_color',
   		'type'    => 'colorpicker',
   		'default' => '#ffffff',
   	) );
   });

2. In first group click to repeat field and populate both https://prnt.sc/13o8bn2

3. Add another group ( Add another Entry )

4. Click move down on first group.

5. See that all works as expected.

6. After moving fields around, try click/dragging repeatable field items

7. Once tested for a bit, save the post.

8. See that data is saved properly.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the code style of this project.
• My code and pull requests meets the Contributing guidelines.