Consider migrating from Tor Launcher to anon-connection-wizard

To get anon-connection-wizard ready to replace Tor-launcher in Tails, we
need:
1. remove all the Whonix-specific part of the acw (Patrick has helped to remove most of the Whonix-specific code of the anon-connection-wizard).
2. make acw translatable by gettext.
3. figure out how torrc is used in Tails.

For problem 3, it turns out:

• it is preferred to let amnesia, rather than root, modify the torrc (https://github.com/micahflee/securedrop-torrc is a workaround to the
  problem)
• it is actually preferred to let anon-connection-wizard to memorize
  the bridges and proxy settings if the user decided to use persistent
  storage.(this may be a complex situation because if we started the
  anon-connection-wizard before user decrypts the persistent storage,
  there will be no previous settings available for users)

Related issues

• Related to #14555 (closed)
• Related to #8243
• Related to #16448 (closed)
• Related to #15709 (closed)
• Related to #17215

Original created by @iry on 15144 (Redmine)