Woocommerce Product Finder 1.5.1

* Fix - Address mishandling of orphaned attributes which could have lead in deprecation notices in newer PHP versions
* Misc - Require WooCommerce to activate the plugin
* Misc - Require PHP 7.4+, WordPress 5.6+ and WooCommerce 7.0+

* Tweak - Tested compatibility up to WC 8.0.
* Tweak - Tested compatibility with WP 6.3.
* Dev - Refactored widget class by extending the class `WC_Widget`.
* Dev - Deprecated class `WC_Product_Finder_Widget`.
* Dev - Updated the minimum requirements to WC 3.7, WP 4.9, and PHP 5.6.

* Feature - Declare compatibility with WooCommerce High-Performance Order Storage (HPOS).
* Tweak - Added links to the plugin settings, the documentation page, and to get support, in the plugin list.
* Tweak - Updated plugin author.
* Tweak - Tested compatibility up to WC 7.6.
* Tweak - Tested compatibility up to WP 6.2.
* Dev - Use SASS instead of LESS for generating the CSS styles.
* Dev - Implement the singleton pattern in the main plugin class.
* Dev - Updated the minimum requirements to WC 3.5, WP 4.7, and PHP 5.4

* Dev - Add branch-labels GH workflow.
* Dev - GH release config and the new PR template.
* Tweak - WC 6.9 compatibility.

* Tweak - WC 6.8 compatibility.

* Tweak - WC 6.7 compatibility.

* Tweak - WooCommerce 6.5 and WordPress 6.0 compatibility.

* Fix - Include languages folder and POT file in the release.
* Tweak - WC 6.2 compatibility.

* Fix - Unify `.github/**.md` files with other repos.
* Tweak - WC 6.1 compatibility.

* Tweak - WC 6.0 compatibility.
* Tweak - WP 5.9 compatibility.