DBZ-7876 Add NATS user/password authentication config options

Add a secondary authentication method to NATS thanks to two new properties: `auth.user` and `auth.password`.
Since JWT/seed was available before this authentication method, they should only be used if JWT auth is not already configured.

debezium-server-nats-jetstream/src/main/java/io/debezium/server/nats/jetstream/NatsJetStreamChangeConsumer.java

@@ -55,6 +55,8 @@ public class NatsJetStreamChangeConsumer extends BaseChangeConsumer
 
     private static final String PROP_AUTH_JWT = PROP_PREFIX + "auth.jwt";
     private static final String PROP_AUTH_SEED = PROP_PREFIX + "auth.seed";
+    private static final String PROP_AUTH_USER = PROP_PREFIX + "auth.user";
+    private static final String PROP_AUTH_PASSWORD = PROP_PREFIX + "auth.password";
 
     private Connection nc;
     private JetStream js;
@@ -68,6 +70,12 @@ public class NatsJetStreamChangeConsumer extends BaseChangeConsumer
     @ConfigProperty(name = PROP_AUTH_SEED)
     Optional<String> seed;
 
+    @ConfigProperty(name = PROP_AUTH_USER)
+    Optional<String> user;
+
+    @ConfigProperty(name = PROP_AUTH_PASSWORD)
+    Optional<String> password;
+
     @Inject
     @CustomConsumerBuilder
     Instance<JetStream> customStreamingConnection;
@@ -94,6 +102,9 @@ void connect() {
                 natsOptionsBuilder
                         .authHandler(Nats.staticCredentials(jwt.get().toCharArray(), seed.get().toCharArray()));
             }
+            else if (user.isPresent() && password.isPresent()) {
+                natsOptionsBuilder.userInfo(user.get(), password.get());
+            }
 
             nc = Nats.connect(natsOptionsBuilder.build());