Use Addressbook names for owners when creating/loading a Safe

[lukasschor]

As a user creating/loading a new Safe, I want to have names of addresses in my address book automatically pre-filled in the name input field.

• Creating Safe
  Whenever user inputs an address into the owner address input field, check if address is in address book and if yes, update the name input field accordingly.

• Loading Safe
  For the owners of the Safe, automatically suggest the names if they are already in the address book.

Note: please be sure that #524 is solved with this enhancement as well