fix: Cleans up file system paths and archiving (#815)

* Makes EnsureDirectory properly work for relative and absolute paths
* Adds a `PathUtility.GetFullPath` which returns full paths for relative paths to `Core.BaseDirectory`. If the path is absolute, it will return as-is.
* Moves EnsureDirectory to `PathUtility`. So `ScriptsHandler.EnsureDirectory` and `AssemblyHandler.EnsureDirectory` are now `PathUtility.EnsureDirectory`
* Fixes crash guard so that it copies accounts properly.
* Changes world save and auto archive to use a random folder name inside of the temp folder.

Projects/UOContent.Tests/Fixtures/ServerFixture.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Reflection;
 using Server.Misc;
 
 namespace Server.Tests
@@ -8,8 +9,8 @@ namespace Server.Tests
         // Global setup
         static ServerFixture()
         {
+            Core.Assembly = Assembly.GetExecutingAssembly();
             Core.LoopContext = new EventLoopContext();
-
             Core.Expansion = Expansion.EJ;
 
             // Load Configurations