Clean up constructors

[gf712]

Throughout shogun we have various constructors with lots of repetitions, e.g. calls to register_params. We could avoid using register_params by using delegating constructors and then only have a single constructor responsible for parameter registration. This would avoid bugs with initialization, which lead to undefined behaviour, and parameter registration.

[karlnapf]

++
Could you maybe post an example PR where this is done, then people have an easier time reproducing it

[gf712]

Sure, I'll start a PR where I pick a class and clean up the constructors and tag it here

[jonpsy]

I think I can give this a shot ;D

[ellikamishra]

I can try this!

[GuoxinYin]

Hello, is anyone working on this right now? If no, I can work on this!

[ArhamaQ]

hey, I am a beginner but have strong C++ knowledge. I think I can resolve this issue. if it is still open. can you assign me this issue?