Auth clients self service

[sirex]

A client with spinta::admin scope, should be able to do a full auth client managment:

POST /auth/clients - create new client, id generuojamas serverio pusėje
GET /auth/clients - get list of all clients, returns only id and name
GET /auth/clients/<uuid> - get info about a single client, returns all fields except secret
PATCH /auth/clients/<uuid> - update client info, including secret
DELETE /auth/clients/<uuid> - delete client

Client with a valid client token, can get its own info, and change password. But can't see other clients, create new clients, or delete own client or change any attributes except password of its own client.

Client model:

{
  "id": "<uuid>",
  "name": "",    # optional, for backwards compatibility
  "secret": "",  # can't be shown, only used when creating new client or changing secret
  "scopes" [],   # List of scopes as strings
}

Currently clients are stored as files, using name as filename. Now filename should be sconstructed from uuid, liek this: xx/xx/rest-of-uuid.yml, where xx/xx are the first uuid characters. But if name is given, then file name should be stored using name.

[Grigorjeva11]

@aurjas Pratestuoti ar scope'u sukurimas per API veikia.