* refactor `del` -> `remove`
* add fileKey
* refactor `remove` -> `adapter.remove` added notice
* we can now use storage adapters internally / directly - Eg. for
TempStore
* store names may not start with `_` this namespace is for internal
stores and will throw an error
* The direct api uses fileKeys but now provides a `fileKey` function
converting a `FS.File` to a SA specific key

@aldeed I’ve made some changes, simplifying the actual storages api and
allowing access for internal / direct use.