`_deprecated_function` has conditional which is checking if third param (replacement) is null. Passing replacement as empty string to this function will fail this test and the end of triggered error will look like this: `Use instead.` instead of `with no alternative available.`. This PR removes all occurrences of empty strings in this function.
* Started on variation changes
* Stock functions
* Variation class
* Bulk change ->id to get_id() to fix variation form display
* Missing status
* Fix add to cart
* Start on stored data save
* save variation
* Save_variations
* Variation edit panel
* Save variations code works.
* Remove stored data code and fix save
* Improve legacy class
* wc_bool_to_string
* prepare_set_attributes
* Use wc_get_products
* More feedback fixes
* Feedback fixes
Mike Jolley
Krzysztof Grabania