bugfixes/enhancements

prevent users from trying to set the console's level to owner
fix issue with setting multiple owners
update/improve unit tests

Tests/ApplicationTests/Mocks/ApplicationConfigurationHandlerMock.cs

@@ -0,0 +1,36 @@
+using SharedLibraryCore.Configuration;
+using SharedLibraryCore.Interfaces;
+using System;
+using System.Threading.Tasks;
+
+namespace ApplicationTests.Mocks
+{
+    class ApplicationConfigurationHandlerMock : IConfigurationHandler<ApplicationConfiguration>
+    {
+        private readonly ApplicationConfiguration _appConfig;
+
+        public ApplicationConfigurationHandlerMock(ApplicationConfiguration configuration)
+        {
+            _appConfig = configuration;
+        }
+
+        public string FileName => "";
+
+        public void Build()
+        {
+            
+        }
+
+        public ApplicationConfiguration Configuration() => _appConfig;
+
+        public Task Save()
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Set(ApplicationConfiguration config)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}