* Add note traits to check for existence and generic conditions
* Add new note type for marketing notes
* Delete marketing notes when opted out
* Add tests for marketing notes
* Remove welcome note
* Remove store notice setting note
* Remove review your experience note
* Add tests for delete_notes_with_name
* Add filter support so that other code can add notes to be deleted on upgrade.
Before 0.10.0 notes had a default content_data of array(). If stored in the database, these notes would be unable to be loaded. This adds some resiliency to the loading so that invalid content_data fields don't break WC_Admin_Note::set_content_data().
Co-authored-by: Christopher Allford <christopher.allford@automattic.com>
Joshua T Flowers
Matt Sherman
Paul Sealock