Store user data encoded

[EvilLord666]

We should encode userdata for preventing it from access via getting access to data storage (Redis, File). Probably each user credentials should be stored as Base-64 encoded string, this feature should be taken into account in Ferrum CLI too

[stdstring]

@EvilLord666 Encoding into Base64 isn't safe by the nature. If we want to protect user data, we must encode/decode their with private/public keys.

[EvilLord666]

base64 here means a way (format) how we string save in JSON, data itself should be encoded/decoded with some encryption key

[EvilLord666]

Here what should we do:

1. For Realm we should create additional non-mapping field PasswordSalt to Realm object
2. When creating a new User we should make a password hash as follows - hash(password+salt), where hash is the hashing func, this algorithm is working for non-federated Users. In the credentials field in the passwordwe store a hash
3. We should have a separate module for hashing and save hash_type to credentials too.
4. Salt must be created automatically when we create Realm; every Realm must have its own salt.