Dynamic property warnings

As of PHP 8.2, dynamic properties are now deprecated. If debug setting are on and displayed, a large number of warning will appear on the site admin page if this plugin is installed and activated.

Deprecated: Creation of dynamic property CSF_Field_group::$field is deprecated in /nas/content/live/testsite/wp-content/plugins/3d-viewer-premium/admin/csf/classes/fields.class.php on line 14
Deprecated: Creation of dynamic property CSF_Field_group::$value is deprecated in /nas/content/live/testsite/wp-content/plugins/3d-viewer-premium/admin/csf/classes/fields.class.php on line 15
Deprecated: Creation of dynamic property CSF_Field_group::$unique is deprecated in /nas/content/live/testsite/wp-content/plugins/3d-viewer-premium/admin/csf/classes/fields.class.php on line 16
Deprecated: Creation of dynamic property CSF_Field_group::$where is deprecated in /nas/content/live/testsite/wp-content/plugins/3d-viewer-premium/admin/csf/classes/fields.class.php on line 17
Deprecated: Creation of dynamic property CSF_Field_group::$parent is deprecated in /nas/content/live/testsite/wp-content/plugins/3d-viewer-premium/admin/csf/classes/fields.class.php on line 18

The fields.class.php file should be updated to declare these and satisfy the PHP 8.2 parser and to prevent any future plugin breakage.

public $field = array();
public $value = '';
public $unique = '';
public $where = '';
public $parent = '';

This also happens in the metabox-options.class.php file for the following fields and should be updated there as well.

public $post_formats = array();
public $page_templates = array();

It is possible that there are other occurrences of undeclared fields in other class files, so it needs to be checked across all of your code.

Thanks for a great plugin, otherwise!