- remove usage of `async` dependency https://github.com/verdaccio/verdaccio/issues/1225
- refactor method storage class
- create new module `core` to reduce the ammount of modules with utilities
- use `undici` instead `node-fetch`
- use `fastify` instead `express` for functional test
### Breaking changes
- plugin storage API changes
- remove old search endpoint (return 404)
- filter local private packages at plugin level
The storage api changes for methods `get`, `add`, `remove` as promise base. The `search` methods also changes and recieves a `query` object that contains all query params from the client.