fix: does not break class loading if direct buffer allocator is not available

[torito]

What's Changed

The Direct Buffer is not always needed to use Arrow memory, however, we cannot load MemoryUtil class if we don't set:

--add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED

Which is not always needed/possible.

This fix proposes to catch the InaccessibleObjectException to not avoiding the load of the class.

The directBuffer is, in any case not available and a UnsupportedOperationException will be throw as it is in the existing code

Closes #1007 .