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/Server/Items/Container.cs

@@ -1823,7 +1823,7 @@ namespace Server.Items
                 {
                     line = line.Trim();
 
-                    if (line.Length == 0 || line.StartsWith("#", StringComparison.Ordinal))
+                    if (line.Length == 0 || line.StartsWithOrdinal("#"))
                     {
                         continue;
                     }