Core/Vehicles: Make the vehicle system more aura driven. Get rid of redundant checks and update relevant data.

Closes #805

src/server/game/Spells/Auras/SpellAuraEffects.cpp

@@ -4269,7 +4269,7 @@ void AuraEffect::HandleAuraControlVehicle(AuraApplication const * aurApp, uint8
 
     if (apply)
     {
-        caster->EnterVehicle(target->GetVehicleKit(), m_amount - 1, aurApp);
+        caster->_EnterVehicle(target->GetVehicleKit(), m_amount - 1, aurApp);
     }
     else
     {
@@ -4282,7 +4282,7 @@ void AuraEffect::HandleAuraControlVehicle(AuraApplication const * aurApp, uint8
 
         // some SPELL_AURA_CONTROL_VEHICLE auras have a dummy effect on the player - remove them
         caster->RemoveAurasDueToSpell(GetId());
-        caster->ExitVehicle();
+        caster->_ExitVehicle();
     }
 }