[BUG] Stop using detail APIs in Java code

**Describe the bug**
There are a large number of libcudf tests that rely on detail APIs. There are parts of the JNI that use detail APIs. detail APIs are internal functionality that should not be called externally.

**Expected behavior**
We should rewrite the offending code to not use detail APIs. If this proves too difficult, that probably indicates that we have functionality hidden in detail namespaces that should be exposed publicly. I suspect that in at least a few cases we will need to add new public APIs to support users, but hopefully not too many of them.

**UPDATE 6/28/2024**
Upon further discussion, we have decided to continue allowing testing of detail APIs because in some contexts that can be useful for unit testing small, internal components of larger APIs. Therefore this issue is now primarily about avoiding usage of detail APIs in the JNI layer.