v20.1 Bank of Mom 2023-01-16

This script adds in the Bank of Mom Feature from GSC or HGSS, where the player's mother will save money and occasionally buy items.
The mom attempts to buy an item after the end of every battle, if she can afford one of the MOM_FIXED_ITEMS or MOM_RANDOM_ITEMS.
If she buys an item, she will call the player after the battle ends.

Several additional, required edits in def pbMessageDisplay to add
the mgoldwindow variable, to show how much money the Bank of Mom holds.

1. Under goldwindow = nil, put mgoldwindow = nil
2. In the long while text regex, add mg| before g|
3. Under:
   
   Ruby:

   when "g"      # Display gold window
     goldwindow&.dispose
     goldwindow = pbDisplayGoldWindow(msgwindow)
   Put:
   
   Ruby:

   when "mg"    # Display mom gold window
     mgoldwindow&.dispose
     mgoldwindow = pbDisplayMomGoldWindow(msgwindow, goldwindow)
4. Under goldwindow&.dispose, put mgoldwindow&.dispose

These edits may have to be made to a plugin if one overrides this method.