Maua client validations and improvements

-Add Score Prediction new legend.
-Remove some depreciated functions and services along the app, since they're no needed anymore.
-Remove old un used variables from practice controller.
-Remove groupId parameter from practice game creation.	
-Remove un used variables from question controller.
-Add validation to ensure game creation over smart practice section. (Avoid possible null 'game_id' inside question presentation request)
-Bring back dashboard integration to redirect to Grockit 1.0 for non GRE' groups.**

**Yesterday I brought back the accordion to the project, it works fine. Right now I have another branch with this component working fine, for now I get rid of it from 'master' in order to continue working as we does along the week.