On going Refactoring plan

[lionelkusch]

The initial refactoring plan associated with the creation of the API 1/2 is to:

• Reformat the class with a new API
• Improve the tests and group them by topic (for example, ADA-SVR ADA-SVR (2/4) Test for models #101)
• Homogenise the documentation
• Add type to the parameter and assertion (for example ADA-SVR ADA-SVR (4/4): adding type and assertion #102)
• Add examples and code snippets (for example ADA-SVR ADA-SVR (4/4) bis PR example of models #100)

[lionelkusch]

The example model has been removed but it can be used to continue the actual refactoring.
An example of the usage of the new API can be found in #268.
The first step is close to being finished with the PR #372, #367, #367 .
The second step has been started in PR #384, #391, #392 and #393 but there is no consensus on how to test the code, as you can see in the issue #375.