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/Special/SoulStone.cs

@@ -129,11 +129,18 @@ namespace Server.Items
             {
                 list.Add(
                     1070721, // Skill stored: ~1_skillname~ ~2_skillamount~
-                    $"#{AosSkillBonuses.GetLabel(Skill)}\t{SkillValue:F1}"
+                    $"{AosSkillBonuses.GetLabel(Skill):#}\t{SkillValue:F1}"
                 );
             }
 
-            list.Add(1041602, LastUserName ?? $"#{1074235}"); // Owner: ~1_val~
+            if (LastUserName != null)
+            {
+                list.Add(1041602, LastUserName); // Owner: ~1_val~
+            }
+            else
+            {
+                list.AddLocalized(1041602, 1074235); // Owner: ~1_val~
+            }
         }
 
         private static bool CheckCombat(Mobile m, TimeSpan time)
@@ -968,7 +975,7 @@ namespace Server.Items
         {
             base.GetProperties(list);
 
-            list.Add(1060584, $"{m_UsesRemaining}"); // uses remaining: ~1_val~
+            list.Add(1060584, m_UsesRemaining); // uses remaining: ~1_val~
         }
 
         public override void Serialize(IGenericWriter writer)