Implement Account creation flow for Sign up

[tomsmith8]

Task

Sign up flow for Account creation:

• [ ] Splash view
• [ ] New User/Existing User view
• [ ] Code view (will be used for invite or self sign up code later, but skipped for now)
• [ ] #680
• [ ] Alias form view
• [ ] Profile Picture view
• [ ] Ready to use Sphinx -> Dashboard

Acceptance Criteria

• Write tests for each stage of the flow so we can test independently

[ariel10aguero]

@tomsmith8 we have changed a little bit the order of the screens to facilitate the flow and to be consistent with the code is already wrote (basically to allow db interaction which is possible in the app when the user is already authenticated)

here is the order:

• Splash
• New User / Existing User
• Code field view
• PIN view
• Connecting view(Seed generation, MQTT)
• Alias form view
• Profile Picture view
• Ready to user Sphinx