Removed the --authorized-withdrawer argument from create-vote-account

The parameter is now a required third argument.  This is because authorized
withdrawer should never be the same as vote account keypair or validator
identity keypair for security reasons.

Added a --allow-unsafe-authorized-withdrawer to override this restriction if
necessary.

cli/tests/vote.rs

@@ -45,7 +45,7 @@ fn test_vote_authorize_and_withdraw() {
         seed: None,
         identity_account: 0,
         authorized_voter: None,
-        authorized_withdrawer: Some(config.signers[0].pubkey()),
+        authorized_withdrawer: config.signers[0].pubkey(),
         commission: 0,
         memo: None,
     };