allow to use action specific sanitization method with model name

[camilova]

Its a common pattern to name strong parameters method with the model's name like patients_params
But it is also common splitting sanitization methods for :create and :update actions, and it can follow the same naming style too like :create_patients_params or update_patients_params as the other style create_params that currently is supported by CanCanCan.

It PR adds support to detect and use as the latest choice the named <action>_<model_name>_params method for sanitization.