Scalability Pro 5.83

* Hardened symlink checker for slow query logger so it doesn't raise warnings

* Fixed removal of symlink to clear the opcache if in use, this means when QM's symlink is put in place it then properly uses Query Monitors symlink
* Added new URL param spro_show_import_queries=1 which can be used with the wp-all-import processing URLs to view the queries with Query Monitor for a batch of rows imported
- e.g. call localhost and then:
- call localhost
- note the alteration of the URL to not use wp-load and instead load your dashboard, and then with spro_show_import_queries=1
- this clones the wp all import processing function but with send_json removed
- this means you can see all the DB activity performed by WP All Import through Query Monitor!!

* Added new detection of unnecessary GROUP BY when LIMIT 0,1 is being used
- this seems to happen in imports and causes a table scan of wp_posts, so this should result in a good boost for imports on large sites
* Added further improvement for 'defer term counting'
- when a new item is published, that post types cache is wiped
- this leads to slower imports since an entire recount can happen after every import
- The change has modified this query to fetch data from our own cache table which stores the counts for 24 hours if you enable the defer term counting option
* Added Optimize Product Attributes Lookup functionality to the Imports tab
- WooCommerce maintains the product attributes table EVEN IF you deselect to use it
- One outstanding issue here on larger sites is the SQL where they check WHERE product_id = 984353 OR product_or_parent_id = 984353;
- only the product_or_parent_id needs to be checked in this case and then an index gets used
- This functionality alters this SQL query if you enable the option on the Imports tab