Add custom user-agent prefix to Route53 calls

This commits adds a prefix to the user-agent header field of the client
that makes requests to AWS Route 53 API. User agent is now prefixed as
in:

User-Agent: dyna53::Route53, ...

This is done to allow explicit identification of (well-behaving, i.e.,
unmodified) Dyna53 traffic if that would be needed at any time from AWS
perspective.

Original idea credits to https://twitter.com/antonbabenko

src/dyna53/src/main/java/com/ongres/labs/dyna53/route53/Route53AsyncClientProvider.java

@@ -7,19 +7,35 @@
 package com.ongres.labs.dyna53.route53;
 
 
+import org.eclipse.microprofile.config.inject.ConfigProperty;
 import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
+import software.amazon.awssdk.core.client.config.ClientOverrideConfiguration;
+import software.amazon.awssdk.core.client.config.SdkAdvancedClientOption;
 import software.amazon.awssdk.http.nio.netty.NettyNioAsyncHttpClient;
 import software.amazon.awssdk.regions.Region;
 import software.amazon.awssdk.services.route53.Route53AsyncClient;
 
+import javax.enterprise.context.ApplicationScoped;
 import javax.enterprise.inject.Produces;
 
 
+@ApplicationScoped
 public class Route53AsyncClientProvider {
+    private static final String DYNA53_ROUTE53_USER_AGENT_PREFIX = "dyna53::Route53";
+
+    @ConfigProperty(name = "route53_aws_profile")
+    String route53AWSProfile;
+
     @Produces
     public Route53AsyncClient provideRoute53AsyncClient() {
         return Route53AsyncClient.builder()
-                .credentialsProvider(ProfileCredentialsProvider.create("dyna53"))
+                // Play nice and provide explicit identification for Dyna53 requests to AWS Route 53 services
+                .overrideConfiguration(
+                        ClientOverrideConfiguration.builder()
+                                .putAdvancedOption(SdkAdvancedClientOption.USER_AGENT_PREFIX, DYNA53_ROUTE53_USER_AGENT_PREFIX)
+                                .build()
+                )
+                .credentialsProvider(ProfileCredentialsProvider.create(route53AWSProfile))
                 .httpClientBuilder(NettyNioAsyncHttpClient.builder())   // Needed by GraalVM native, reflection issues
                 .region(Region.AWS_GLOBAL)
                 .build();