Consider improving misconfiguration handling

Currently, a failure to configure the SDK results in the issues like below in WF.

We could validate required parameters by the protocol, but then that would require us to mimics validation and property resolution the same way like the SDK will do just so that we could present a slightly better error message (e.g. without mention to NPE).

Does not seem worth it.

20:11:28,605 ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 43) MSC000001: Failed to start null: org.jboss.msc.service.StartException in anonymous service: java.util.concurrent.CompletionException: java.lang.IllegalStateException: java.lang.NullPointerException: region must not be null.
	at org.wildfly.service@32.0.0.Beta4//org.wildfly.service.Installer$NonBlockingValueService.lambda$start$2(Installer.java:819)
	at java.base/java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:863)
	at java.base/java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:841)
	at java.base/java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:510)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1773)
	at org.jboss.threads@3.9.2//org.jboss.threads.ContextHandler$1.runWith(ContextHandler.java:18)
	at org.jboss.threads@3.9.2//org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2651)
	at org.jboss.threads@3.9.2//org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2630)
	at org.jboss.threads@3.9.2//org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1622)
	at org.jboss.threads@3.9.2//org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1589)
	at java.base/java.lang.Thread.run(Thread.java:840)
	at org.jboss.threads@3.9.2//org.jboss.threads.JBossThread.run(JBossThread.java:501)
Caused by: java.util.concurrent.CompletionException: java.lang.IllegalStateException: java.lang.NullPointerException: region must not be null.
	at java.base/java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:315)
	at java.base/java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:320)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1770)
	... 7 more
Caused by: java.lang.IllegalStateException: java.lang.NullPointerException: region must not be null.
	at org.jboss.as.clustering.jgroups@40.0.0.Beta1-SNAPSHOT//org.jboss.as.clustering.jgroups.subsystem.AbstractChannelResourceDefinitionRegistrar$3.get(AbstractChannelResourceDefinitionRegistrar.java:253)
	at org.jboss.as.clustering.jgroups@40.0.0.Beta1-SNAPSHOT//org.jboss.as.clustering.jgroups.subsystem.AbstractChannelResourceDefinitionRegistrar$3.get(AbstractChannelResourceDefinitionRegistrar.java:229)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
	... 7 more
Caused by: java.lang.NullPointerException: region must not be null.
	at software.amazon.awssdk.s3//software.amazon.awssdk.utils.Validate.paramNotBlank(Validate.java:177)
	at software.amazon.awssdk.s3//software.amazon.awssdk.regions.Region.of(Region.java:181)
	at software.amazon.awssdk.s3//software.amazon.awssdk.regions.Region.of(Region.java:177)
	at org.jgroups.aws@4.0.2.Final-SNAPSHOT//org.jgroups.protocols.aws.S3_PING.init(S3_PING.java:128)
	at org.jgroups@5.5.3.Final//org.jgroups.stack.ProtocolStack.initProtocolStack(ProtocolStack.java:810)
	at org.jgroups@5.5.3.Final//org.jgroups.stack.ProtocolStack.initProtocolStack(ProtocolStack.java:795)
	at org.jgroups@5.5.3.Final//org.jgroups.stack.ProtocolStack.init(ProtocolStack.java:789)
	at org.jgroups@5.5.3.Final//org.jgroups.JChannel.<init>(JChannel.java:163)
	at org.jboss.as.clustering.jgroups@40.0.0.Beta1-SNAPSHOT//org.jboss.as.clustering.jgroups.JChannelFactory.createChannel(JChannelFactory.java:121)
	at org.jboss.as.clustering.jgroups@40.0.0.Beta1-SNAPSHOT//org.jboss.as.clustering.jgroups.JChannelFactory.createChannel(JChannelFactory.java:108)
	at org.jboss.as.clustering.jgroups@40.0.0.Beta1-SNAPSHOT//org.jboss.as.clustering.jgroups.subsystem.AbstractChannelResourceDefinitionRegistrar$3.get(AbstractChannelResourceDefinitionRegistrar.java:234)
	... 9 more

Start at S3_PING.java:128, where the missing region triggers the reported failure, and inspect the surrounding configuration path in AbstractChannelResourceDefinitionRegistrar at lines 229-253. Reproduce the misconfiguration and define a concrete user-facing handling behavior; done means that behavior is implemented and the failure no longer produces the reported unhelpful stack trace.