Spellcasting restrictions are checked before spellcasting animations are played

In vanilla MW if player can't cast spell (e.g. due to low magicka) visual spell effects, player casting animation and tooltip are shown.

in OpenMW only tooltip "You cannot cast spell..." is shown.

(RM-4227 from redmine: created on 2017-11-25 by Grigory Latyshev, )