[Junit5 extension] Add Interception of @ParameterizedTest to JUnit Open Feature Extension

[sebastian-zahrhuber]

If the JUnit Open Feature Extension is used, a developer needs to use the @Flag annotation on @Test and @ParameterizedTest methods.

By intercepting the test method, the OpenFeatureExtension sets the current namespace for the TestProvider which is used later on in the evaluation. This is done by implementing the interface InvocationInterceptor and overriding the method interceptTestMethod.
Actually, the method interceptTestMethod does not intercept methods annotated with @ParameterizedTest. This leads to the issue that during the feature flag evaluation, the current namespace is not set int the TestProvider and therefore, the flag values cannot be stubbed with the annotation @Flag.
To fix the issue not only the method interceptTestMethod must be overridden, but InvocationInterceptor.interceptTestTemplateMethod() must be overridden as well.

A/C

@Flag annotation mocks feature flags on test methods annotated with @test and @ParameterizedTest

[beeme1mr]

Hey @sebastian-zahrhuber, is this something you'd be willing to work on? FYI @aepfli.

[aepfli]

it seems like this issue also relates somehow to #957

[sebastian-zahrhuber]

Hi @beeme1mr , to be honest, we don't have many resources left in the team, but if it speeds up the process, I can take this issue since we currently depend on the change