Implement simple sync/async key value storage interface with version support

[jhnns]

The web offers some simple key-value storage interfaces, such as localStorage, sessionStorage, or adapters for indexedDB.

However, using these storage options can cause a few problems in large applications or over a longer period of time:

• Keys can overlap (no warning if two code locations use the same key)
• Migration is not taken into account: how to deal with it if a different/new data format is needed
• If the logout process takes a little longer, it can happen that data is still written even after logging out and thus continues to exist after logging out
• Serializing and deserializing might not be loss-less, e.g. undefined with JSON.stringify

The implementation should:

• Provide some kind of registry that prevents multiple code locations using the same key
• Work with version numbers immediately so that simple migrations can be written
• Offer a kind of kill switch (e.g., a drop() method) after which it is no longer possible to write to storage
• Offer a custom strategy for JSON.parse