Use set_config for SetConfig and UpdateConfig

[imobachgs]

Problem

Using a minimal PATCH call including only a product does not trigger the storage proposal:

{
  "product": { "id": "Tumbleweed }
}

Solution

Use always the set_config function to update the configuration.

• PATCH: will merge the configuration (the current and the new one) and will update all the services. In the case of storage, it means it receives a None configuration, which causes to reset the proposal.
• PUT: send the given configuration to all the service.

Follow-up

Although SetConfig messages will handle a config: Some<Config> value, we should review how it is interpreted by each service.