Remove RippleAddress:

The RippleAddress class was used to represent a number of fundamentally
different types: account public keys, account secret keys, node public
keys, node secret keys, seeds and generators.

The class is replaced by the following types:
* PublicKey for account and node public keys
* SecretKey for account and node private keys
* Generator for generating secp256k1 accounts
* Seed for account, node and generator seeds

src/ripple/app/tests/Regression_test.cpp

@@ -146,7 +146,7 @@ struct Regression_test : public beast::unit_test::suite
                 (sfSigningPubKey, std::move(pubKeyBlob.first));
             jt.stx.reset (secp256r1Sig.release());
 
-            env (jt, ter (temINVALID));
+            env (jt, ter (temBAD_SIGNATURE));
         };
 
         Account const alice {"alice", KeyType::secp256k1};