[Java] Encapsulate on-heap float arrays into Dataset (rapidsai#1024)

This PR is a follow-up from rapidsai#902.
Still WIP (see self-comments on the changes) but I'd like some early feedback.

Authors:
  - Lorenzo Dematté (https://github.com/ldematte)
  - MithunR (https://github.com/mythrocks)

Approvers:
  - Chris Hegarty (https://github.com/ChrisHegarty)
  - MithunR (https://github.com/mythrocks)

URL: rapidsai#1024

Author: ldematte

java/cuvs-java/src/main/java22/com/nvidia/cuvs/spi/JDKProvider.java

@@ -38,6 +38,10 @@
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import com.nvidia.cuvs.internal.ScalarQuantizerImpl;
+import com.nvidia.cuvs.internal.common.Util;
+import java.lang.foreign.Arena;
+import java.lang.foreign.MemoryLayout;
+import java.lang.foreign.MemorySegment;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.Objects;