Add support for challenge/response authentication

...va/org/sdnplatform/sync/thrift/AuthChallengeResponse.java

lib/gen-java/org/sdnplatform/sync/thrift/AuthScheme.java

lib/gen-java/org/sdnplatform/sync/thrift/HelloMessage.java

src/main/java/org/sdnplatform/sync/client/SyncClient.java

src/main/java/org/sdnplatform/sync/error/AuthException.java

...org/sdnplatform/sync/error/InconsistentDataException.java

.../org/sdnplatform/sync/error/ObsoleteVersionException.java

...ain/java/org/sdnplatform/sync/error/PersistException.java

...va/org/sdnplatform/sync/error/SerializationException.java

src/main/java/org/sdnplatform/sync/error/SyncException.java

...ava/org/sdnplatform/sync/error/UnknownStoreException.java

...java/org/sdnplatform/sync/internal/config/AuthScheme.java

...a/org/sdnplatform/sync/internal/config/ClusterConfig.java

.../sdnplatform/sync/internal/config/PropertyCCProvider.java

...sdnplatform/sync/internal/config/SyncStoreCCProvider.java

...sdnplatform/sync/internal/config/bootstrap/Bootstrap.java

...nc/internal/config/bootstrap/BootstrapChannelHandler.java

...atform/sync/internal/remote/RemoteSyncChannelHandler.java

...rg/sdnplatform/sync/internal/remote/RemoteSyncFuture.java

...g/sdnplatform/sync/internal/remote/RemoteSyncManager.java