Objective 2, Activity 2: Notify users about typo errors when entering .onion addresses
This is the parent ticket to hold any tickets under this activity, including:
- Using the address format of onion services v3 that allows us to detect typos.
- Experimenting with the optimal user experience for this error case, e.g. offering a retry-button after explaining what went wrong.
- Implementing a special error page that tells the user the problem is a typo in the address.