fix(core): Optimizes strings / .NET 5 compatibility changes (#354)

- [X] Removes some string allocations (e.g. split)
- [X] Optimizes some collections
- [X] Converts insensitive to extension methods of built-ins.
- [X] Adds ordinal (case sensitive) string helpers
- [X] Fixes conditionals for in-game commands so they use Ordinal comparisons.
- [X] Replaces ToLower.Contains with InsensitiveContains
- [X] Adds ValueStringBuilder
- [X] Implements ValueStringBuilder in a few places where it makes sense
- [X] Removes the redundant Wrap function and replaces it with an optimized version
- [X] Fixes list conversions in Utility

Closes #351

Bumps release version

Projects/UOContent/Engines/Spawners/BaseSpawner.cs

@@ -519,7 +519,7 @@ namespace Server.Engines.Spawners
 
                     for (var j = 0; thisProp == null && j < allProps.Length; ++j)
                     {
-                        if (Insensitive.Equals(propName, allProps[j].Name))
+                        if (propName.InsensitiveEquals(allProps[j].Name))
                         {
                             thisProp = allProps[j];
                         }