Level 20 chocobos - Make them a little different?

[Felis]

Their stats grow with the players level (so in 3.0)
Choco level is the current Player level and role rank is just role rank and not the level.

It is like during the early 1.0, where stats of a character depended of the physical level and were not part of the class rank (it was possible to have 500 int with a lv 1 THM if the physical level was high enough).