Make flash messages fixed and sticked to bottom
Created by: mbajur
According to #4653 i've remade flash messages in a more user friendly way. They are different than in a screenshot attached to the issue cause they looked ugly that way. Idecided to make them exactly as they were but for now, they are semi transparent (80%) and sticked to bottom of the screen.
I've also reduced fadeOut timeout to 3000 ms cause they don't need to last so long.