[Code Update - Chapter 04] Code update for MP OpenAPI 4.1

[ttelang]

Below are the list of changes:

pom.xml

• Updating dependencies for Fault Tolerance 4.1 (MicroProfile 7.1)
• Migrating to Java 21

PaymentResource.java

• Updated with new methods to demonstrate New MicroProfile OpenAPI 4.1 features

CustomModelReader.java

• Custom OpenAPI model reader class demonstrating support for jsonSchemaDialect.

ExtensionFilter.java

• A new class to demonstrate the use of getExtension() and hasExtension() methods.

SecuredProductApplication.java

• Demonstrates how to document multiple security mechanisms for your API.

AsyncRequest.java and ProcessResult.java

• New entity classes used to demonstrate the documentation of async APIs

ConditionalProduct.java

• Class to demonstrates the @DependentRequired annotation in MicroProfile OpenAPI 4.1.

ProductRecord.java

• Demonstrates support for Java Records.

ProductWithOptional.java

• Demonstrates support for Optional types.