Custom arrays are not serialized properly by CacheObjectBinaryProcessorImpl

If to put a custom object array into a cache like this one

            TestObject[] arr = new TestObject[] {new TestObject(i)};

            cache.put(0, arr);

then it will be serialized as Object[] array in CacheObjectBinaryProcessorImpl.marshallToBinary method.

This leads to the situation when object's array type is lost and on cache.get the code below produces ClassCastException

TestObject[] obj = cache.get(i);

The full test is already added into GridCacheBinaryObjectsAbstractSelfTest.testCustomArrays.

To fix the issue we have to revisit logic of CacheObjectBinaryProcessorImpl.marshallToBinary and CacheObjectContext.unwrapBinary.