Group experimental declarations

[LVMVRQUXL]

🤔 The problem

Our experimental APIs are dispatched in different packages.
This practice encourages us to add the corresponding annotation in the kotools.types.experimental package without putting the marked declaration in the same package. It also pollutes the documentation of the stable API that should contain stable declarations.

💡 The idea

The idea is to move the experimental declarations to the kotools.types.experimental package and to replace their experimental annotation by the ExperimentalKotoolsTypesApi annotation.
Grouping these declarations in the same package will also favor using extension functions and composition over inheritance.

🙏 Help needed

Please give this post a reaction if you are interested in this change and comment below your thoughts on it.
We would love to have your feedback!

[LVMVRQUXL]

This idea will be implemented by the issue #319.