Add new snippet for @QuarkusIntegrationTest

[datho7561]

See redhat-developer/vscode-quarkus#551

It seems like the class @SubstrateTest no longer exists in newer versions of Quarkus. This means that the qntrc snippet doesn't appear. According to https://quarkus.io/guides/building-native-image#testing-the-native-executable, the recommended way to create a test that can test the binary is making a class annotated with @QuarkusIntegrationTest.

Instead of replacing qntrc, I think it makes sense to provide a new snippet with its context set to detect the presence of the @QuarkusIntegrationTest annotation, so that the old snippet is still present in older versions of Quarkus.