Update BaseWorkTypes.xml

Added translations to all descriptions. 
Also fixed:
1. Artist - "Артист" to "Искусствовед" (In Russian "Артист" means "performer") 
2. Cooker - "Кок" to "Повар" ("Кок" means cooker on the ship or boat)
3. Firefighter -  "Пожарник" to "Пожарный" ("Пожарник" is about a person, who survived the fire)