Make sure default platforms recommended by registries have higher preferences than those referenced from downstream platforms

[aloubyansky]

This change includes a test that illustrates the use-case.

Basically, when two registries are configured and the primary one recommends a platform based on a Quarkus version that is not promoted anymore by the second registry, when a user creates a new projects using extensions from the platform from the second registry, the latest version of the platform provided by the second registry should be selected.

Before this change, the registry client would select a platform version that was based on the same version Quarkus that the primary registry recommends.

[quarkus-bot]

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Flaky tests - Develocity

⚙️ JVM Tests - JDK 21

📦 extensions/infinispan-cache/deployment

✖ io.quarkus.cache.infinispan.InfinispanCacheTest.testGetAsyncWithParallelCalls - History

• expected: "thread1" but was: "thread2" - org.opentest4j.AssertionFailedError

org.opentest4j.AssertionFailedError: 

expected: "thread1"
 but was: "thread2"
	at io.quarkus.cache.infinispan.InfinispanCacheTest.testGetAsyncWithParallelCalls(InfinispanCacheTest.java:283)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at io.quarkus.test.QuarkusUnitTest.runExtensionMethod(QuarkusUnitTest.java:521)
	at io.quarkus.test.QuarkusUnitTest.interceptTestMethod(QuarkusUnitTest.java:435)

[gsmet]

@aloubyansky is it something we want to backport?

[aloubyansky]

I think we could backport it.
Generally, it's not changing how extensions are selected in case when both the Red Hat and the community registries are configured due to how the Red Hat platform is built.
The difference will be seen when platforms from different registries provide different extensions. So this will make sense for orgs that build their custom platforms and setup their own registries.