Problem/Motivation
Responsive image style is deleted when a mapped (or fallback) image style gets deleted. This is because of unresolved dependency.
Proposed resolution
Implement onDependencyRemoval() and: DECIDE WHAT TO DO!
Note that on image style deletion the user is able to provide a replacement that can be used to replace the deleted style in responsive image style.
Remaining tasks
None.
User interface changes
None.
API changes
None.
