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/products/product_history.php

@@ -80,6 +80,7 @@
         type: 'POST',
         url: '/products/get_product_history_table/client_id=' + client_id + '&product_id=' + product_id + '&campaign_id=' + campaign_id + '&ad_group_id=' + ad_group_id,
       },
+      stateSave: true,
       autoWidth: false,
       lengthChange: false,
       pageLength: 30,