feat: Add Gemini AI integration for product title and description optimization

- Implemented Gemini API service for generating optimized product titles and descriptions based on Google Merchant Center guidelines.
- Added settings for Gemini API key and model selection in user settings.
- Enhanced product management views to support AI-generated suggestions for titles and descriptions.
- Enabled state saving for various data tables across campaign, terms, logs, and products views.
- Introduced AI prompt templates for generating product descriptions and categories.

templates/facebook_ads/main_view.php

@@ -250,6 +250,7 @@ function fb_reload_table()
   ];
 
   new DataTable( '#fb_history_table', {
+    stateSave: true,
     ajax: {
       type: 'POST',
       url: '/facebook_ads/get_history_data_table',