Deprecate HibernateValidatorFactoryCustomizer in favor of ValidatorFactoryCustomizer

[gsmet]

And document it.
While working on the documentation, I realized that we are referencing
ValidatorFactory everywhere so it makes no sense to call the customizer
with the Hibernate prefix.

For now, I deprecated the interface, it will be dropped in the next minor version
as it was only in one micro and the usage is relatively narrow.

[yrodiere]

I think the deprecation would be better handled with simply inheritance, and I'm not sure the renaming is legitimate (see comments below).

Let's just discuss it. If you disagree with me, I'll approve anyway; it's your extension after all :)

[quarkus-bot]

Failing Jobs - Building 71ee592

Status	Name	Step	Failures	Logs	Raw logs
✖	Gradle Tests - JDK 11	Build	Failures	Logs	Raw logs
✔️	Gradle Tests - JDK 11 Windows

Full information is available in the Build summary check run.

Failures

⚙️ Gradle Tests - JDK 11 #

- Failing: integration-tests/gradle 

📦 integration-tests/gradle

✖ io.quarkus.gradle.devmode.CompositeBuildWithDependenciesDevModeTest.main line 24 - More details - Source on GitHub

org.awaitility.core.ConditionTimeoutException: Condition with lambda expression in io.quarkus.test.devmode.util.DevModeTestUtils that uses java.util.function.Supplier, java.util.function.Supplierjava.util.concurrent.atomic.AtomicReference, java.util.concurrent.atomic.AtomicReferencejava.lang.String, java.lang.Stringboolean was not fulfilled within 1 minutes.
	at org.awaitility.core.ConditionAwaiter.await(ConditionAwaiter.java:167)
	at org.awaitility.core.CallableCondition.await(CallableCondition.java:78)