* Allow Backend::for_keys_in_child_storage to be aborted by the closure
* Ext::kill_child_storage now takes an upper limit for backend deletion
* Add Storage::storage_kill_limited() runtime interface
* review: Use a new version of kill_storage instead of a new interface
* review: Simplify boolean expression
Co-authored-by: cheme <emericchevalier.pro@gmail.com>
* review: Rename for_keys_in_child_storage
Co-authored-by: cheme <emericchevalier.pro@gmail.com>