* Closes#5863
The "dateLibrary" option for java, sadly, sets a mustache value "java8". This change updates this so that "java" in the mustache
libraries means what it should mean - use all java8 classes. In this case, there's no need for the third party Base64 library
as java8's JDK has this built in. In my view, the "dateLibrary" should be deprecated but that should be a separate PR.
* Closes#5954
built and ran tests/samples
* Disable Jackson FAIL_ON_INVALID_SUBTYPE in feign
With this change, Jackson does not fail even if it doesn't recognize a
discriminator type name. This is helpful when upgrading a microservice with
a new subtype while keeping compatibility with its old clients. The instance
is returned as null instead of throwing an exception deep in the feign
framework, allowing clients to gracefully degrade.
* Disable FAIL_ON_INVALID_SUBTYPE for all Jackson-based projects
