fix: Fixes localization corner cases with OPL (#1050)

## Changes
- [X] Adds OPL convenience methods
    - `opl.Add(cliloc, value)` and `opl.Add(value)` - value as an integer or string works just like `opl.Add(cliloc, $"{value}")`
    - `opl.AddLocalized(cliloc, clilocValue)` - works the same as `opl.Add(cliloc, $"#{clilocValue}");`
- [X] Simplifies basic `list.Add()` situations
- [X] Changes cliloc as an argument so it works with custom IPropertyList implementations (HTML)
- [X] Fixes plants so they support the old localization and new (changed in 7.0.12.0+)
- [X] Exposes more methods to override for Item to make creating custom OPL possible.

## Important Notes
* Using a ternary as an argument, like this `opl.Add(number, showType ? $"{type}\t{value}" : $"{value}");` _will not use the correct string interpolation_. This means if you use a custom PropertyList (for HTML or some other purpose), the property list won't be localized properly.
* All localization values must be interpolated, even if they are literal strings, or integers. Example: `opl.Add(number, $"{"Charges"}\t{m_Charges}");` is correct. Using the following: `$"Charges\t{m_Charges}"` will not work for custom PropertyList implementations!

Projects/UOContent/Items/Resources/Blacksmithing/Ingots.cs

@@ -72,7 +72,7 @@ namespace Server.Items
         {
             if (Amount > 1)
             {
-                list.Add(1050039, $"{Amount}\t#{1027154}"); // ~1_NUMBER~ ~2_ITEMNAME~
+                list.Add(1050039, $"{Amount}\t{1027154:#}"); // ~1_NUMBER~ ~2_ITEMNAME~
             }
             else
             {