WooCommerce Lightspeed POS Integration 2.16.7

* New - **MAJOR CHANGE** ALL syncing is now done with the action scheduler queue
* New - Lightspeed Import page can now search for SKU values, Category values, as well as regular and sale prices via the search input
* New - New "Remove Uncategorized" setting which will attempt at removing the "Uncategorized" category when importing products from Lightspeed
* New - New "Category Sync Settings" tab that is specific to categories
* Fix - Bulk editing through the Woo page should now queue changes up instead of causing 429 errors
* Fix - Removes the "WCLSI_UPDATE_CANCELLED_ORDER" option which can cause sync failures
* Fix - JS fix around the case where there are 0 categories to import from Lightspeed
* Tweak - Removed "Order Sync" settings
* Tweak - Removed "Manual "
* Tweak - Disable the "Search Lightspeed" button if the plugin has not being initiated yet
* Tweak - Sets a default '0.0' value for WCLSI_DB_VERSION_OPTION so DB migrations run better
* Tweak - On Category import, try and match Lightspeed categories to ones that already exist in Woo
* Tweak - When pushing a product to Lightspeed from Woo (creating a new product), refresh the page
* Tweak - When pushing a product to Lightspeed from Woo, use the lowest level category id that is linked to Lightspeed for propery category matching

Fix - Upgrade routine that will clear out bad webstore data in the DB - more specifically drops records with item_e_commerce_id values that are NULL
Tweak - Insert Webstore data validation - don't insert item_e_commerce data unless there's an item_e_commerce_id associated with it!
Tweak - Sale Price should not be synced back to Lightspeed as $0.00 if it's an empty string, should now sync back as "Default" price in Lightspeed
Tweak - Redirect to main Lightspeed import page after clearing out the WCLSI tables so the URL param is purged and we're not clearing out products on subsequent requests!

* Fix - Fixes a bug where if the "WCLSI_LAST_LOAD_TIMESTAMP" option is deleted, it is not regenerated, and the check_for_new_ls_prods background job ceases to run
* Fix - Fixes a bug where if an product attribute failed to import, it would fail to import a matrix product. Now the plugin will log an error instead.
* Tweak - Remove console.log() call in JS file