As the result of discussion in T7458,
we need to rename all efl_model based classes with efl_XXX_Model sequence.
I've run few vote for this, see V42, V43
few classes are totally renamed as our consideration of misnaming.
I worried about Efl.Io.Model changes, cause it is widely used,
but as I tested, there is no issue found yet.
Eldbus.Model also may can changed Efl.Dbus.Model,
but I cannot found any class who using Efl.Dbus namespace,
so I left it future work.