Cleans up IIOHelper and removes methods/props that shouldn't exist, changes test helper to use WorkingDirectory fixes some usages of MapPath

src/Umbraco.Tests.Integration/Testing/UmbracoIntegrationTest.cs

@@ -127,7 +127,7 @@ namespace Umbraco.Tests.Integration.Testing
             Services = app.ApplicationServices;
 
             // This will create a db, install the schema and ensure the app is configured to run
-            app.UseTestLocalDb(Path.Combine(testHelper.CurrentAssemblyDirectory, "LocalDb"), this);
+            app.UseTestLocalDb(Services.GetRequiredService<IHostEnvironment>(), this);
 
             app.UseUmbracoCore();
         }