PROPOSAL: Provide a GroupButtonOptions as an immutable class for configuration purpose

[wer-mathurin]

@Frezyx

Adding an object like:
GroupButtonOptions(TextAlign, Padding, etc...)

This will make easier to add option(s) in the future and make the source code more readable.
So we pass one object throw the classes hierarchy instead of duplicating variable across classes, this will make the maintenance of the library more easy.

[Frezyx]

Hello @wer-mathurin !
That is cool thing.

This functionality is open for development

[gnassro]

i think this issue is fixed #68

[Frezyx]

Hello @wer-mathurin !
I implement it in #66