Components Bug: Cast key select and multi-select IDs to string (#2690)

* check for null/is_array

* Cast multi-select IDs to string

A field with integer keys for a multi-select was causing a failure saving a new/existing multi-select button group value.

* Fix for key select as well

Author: cairocoder01

dt-core/utilities/dt-components.php

@@ -129,7 +129,7 @@ public static function render_key_select( $field_key, $fields, $post, $params =
 
         $options = array_map(function ( $key, $value ) use ( $params ) {
             $option = [
-                'id' => $key,
+                'id' => (string) $key,
                 'label' => $value['label'],
             ];
             if ( !isset( $params['key_select']['disable_color'] ) ) {
@@ -163,7 +163,7 @@ public static function render_multi_select( $field_key, $fields, $post, $params
         $options_array = $fields[$field_key]['default'];
         $options_array = array_map(function ( $key, $value ) {
             return [
-                'id' => $key,
+                'id' => (string) $key,
                 'label' => $value['label'] ?? $key,
                 'color' => $value['color'] ?? null,
                 'icon' => $value['icon'] ?? null,