Design solution to allow to renew or add datacap to already verified clients

[josepablofm78]

In a future version of the spec actors, it will be possible to add more datacap to already verified clients. We need to:

• [ ] Implement the method in the API to call this new functionality of the spec actor
• [ ] Design the screens in the frontend app to allow Notary to add new datacap to a verified client
• [ ] (Re)Design the flow in github to allow verified clients to request more datacap to a notary