WIP: Remove corp employees as objects (#143)

* Removed employees as objects from corporations
* Remove employees from office JSON after loading / convert to new parameters
* Showed down morale/etc gain; added optional position to hireEmployee
* enum support for corp employee positions

Mostly authored-by: Kelenius <kelenius@ya.ru>

src/Netscript/RamCostGenerator.ts

@@ -393,7 +393,6 @@ const corporation = {
   getPurchaseWarehouseCost: 0,
   getUpgradeWarehouseCost: 0,
   hasWarehouse: 0,
-  assignJob: 0,
   hireEmployee: 0,
   upgradeOfficeSize: 0,
   throwParty: 0,
@@ -401,7 +400,6 @@ const corporation = {
   hireAdVert: 0,
   research: 0,
   getOffice: 0,
-  getEmployee: 0,
   getHireAdVertCost: 0,
   getHireAdVertCount: 0,
   getResearchCost: 0,