* Tweak - Fetch only the necessary fields when getting the Mailchimp lists.
* Tweak - Get all Mailchimp lists instead of only the first 10 lists.
* Tweak - Tested compatibility with WC 5.4
* Feature - Refresh the provider lists on the settings page.
* Feature - Refresh the subscription stats in the dashboard widget.
* Tweak - Tested compatibility up to WC 5.3.