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/Commands/SignParser.cs

@@ -108,7 +108,7 @@ namespace Server.Commands
 
             Item sign;
 
-            if (name.StartsWith("#", StringComparison.Ordinal))
+            if (name.StartsWithOrdinal("#"))
             {
                 sign = new LocalizedSign(itemID, Utility.ToInt32(name.Substring(1)));
             }