Handle Error, Timeout and Credentials desync in the Wear app

[ThomazFB]

As the authentication step main flow is done, we need to ensure some corner cases are covered, such as:

• Phone connection unavailable during first sign in
• Credentials request to Phone timeout
• App data is wiped and Credentials / site data becomes unavailable

### Tasks
- [ ] React to Phone unavailability with the Login error screen
- [ ] Detect when the Phone credentials request takes too long to respond with the Login error screen
- [ ] Ensure the app recovers from a data wipe (if applicable)

[dangermattic]

Thanks for reporting! 👍