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.Tests/Tests/Firewall/FirewallEntryTests.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Net;
+using Xunit;
+
+namespace Server.Tests
+{
+    public class FirewallEntryTests
+    {
+        [Theory]
+        [InlineData("192.168.1.1/24", typeof(Firewall.CIDRFirewallEntry), "192.168.1.50")]
+        [InlineData("192.168.*.100-200", typeof(Firewall.WildcardIPFirewallEntry), "192.168.30.150")]
+        [InlineData("::1234:*:1000-1234", typeof(Firewall.WildcardIPFirewallEntry), "::1234:5678:1150")]
+        public void TestFirewallEntry(string entry, Type entryType, string ipToMatch)
+        {
+            var firewallEntry = Firewall.ToFirewallEntry(entry);
+            Assert.IsType(entryType, firewallEntry);
+            Assert.True(firewallEntry.IsBlocked(IPAddress.Parse(ipToMatch)));
+        }
+    }
+}