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/Engines/CannedEvil/ChampionSpawn.cs

@@ -945,12 +945,11 @@ namespace Server.Engines.CannedEvil
 
             if (m_Active)
             {
-                list.Add(1060742); // active
-                list.Add(1060658, $"Type\t{m_Type}"); // ~1_val~: ~2_val~
-                list.Add(1060659, $"Level\t{Level}"); // ~1_val~: ~2_val~
+                list.Add(1060742);                         // active
+                list.Add(1060658, $"{"Type"}\t{m_Type}"); // ~1_val~: ~2_val~
+                list.Add(1060659, $"{"Level"}\t{Level}"); // ~1_val~: ~2_val~
                 var killRatio = 100.0 * ((double)m_Kills / MaxKills);
-                list.Add(1060660, $"Kills\t{m_Kills} of {MaxKills} ({killRatio:F1}%)"); // ~1_val~: ~2_val~
-                //list.Add(1060661, "Spawn Range\t{0}", m_SpawnRange); // ~1_val~: ~2_val~
+                list.Add(1060660, $"{"Kills"}\t{m_Kills} of {MaxKills} ({killRatio:F1}%)"); // ~1_val~: ~2_val~
             }
             else
             {