Added Withdraw-X to BoB and Prifddinas bank chest.

-Support for the new bankscreen withdrawal method "Withdraw-X to BoB" 
-Bankscreen.withdraw and overloaded functions now contain an optional boolean (default false) for withdrawing-x normally versus withdrawing-x to the beast of burden familiar.
-Added BANK_CHEST_PRIFDDINAS (supports both popular bank chests in the main Elf City)
-Edited range in line 2074 with new bank chest accordingly 
-Fixed typo "optn" -> "open"
-Added/updated corresponding comments/documentation

If no familiar is present when the Withdraw-X to BoB option is selected, the enter amount dialogue never appears, so __enterAmount times out normally.