IGNITE-6499 : Compact NULL fields binary representation

[hostettler]

To compress binary objects, this patch does the following:
In the case of standard objects (Not implementing Binarylizable or Externalizble) (though the nested objects can):

• It removes the 0x65 that encode null within the object
• It removes the offset from the foot to null objects.
• It adds a null mask at the end of the footer in which each bit is set for non null objects.

[alamar]

What happens when C++ thin client, C# thin client, Python thin client, etc, encounter such BinaryObject's? Do you have tests? What is your plan here? Will they be unaffected?

[hostettler]

I must admit that I do not know. I would need the help of someone more knowledgeable about these clients

[alamar]

I think this means the behavior should be off by default, to be enabled explicitly.

[alamar]

Oh, I can see that you already have the configuration setting implemented. Sorry.