[Java] add copy and deepCopy api for fury

[mof-dev-3]

It is a common use case to copy/deepCopy Java objects.
Before Fury, we used Kryo, which offers copy/deepCopy APIs.
We are trying to migrate from Kryo to Fury because the latter offers better performance.

Maybe consider adding the copy and deepCopy APIs, making it easier for users to migrate with less effort.

[chaokunyang]

@mof-dev-3 We have an issue for this in #1014, but no one has time to take over. Would you like to take a look at it ?

[quhw]

According to my benchmark, fury's serialize+deserialize is a little slower than kryo's copy.

[chaokunyang]

According to my benchmark, fury's serialize+deserialize is a little slower than kryo's copy.

@quhw kryo's copy will skip serialization, it just assign object attributes. but it you use fury serialize+deserialize to mock copy, there will be extra copy introduced by serialization, especially for immutable types such as string/primitives. Kryo will skip copy by just return the original object in its copy interface implementation, but if you use serialize+deserialize to mock it, the copy will introduce extra cost.

I think the proposal in #1014 can address this issue