Simplify targetClass retrieval in ImplementInterfaceCommand

Author: Vogel612

Rubberduck.Core/UI/Command/Refactorings/RefactorImplementInterfaceCommand.cs

@@ -33,10 +33,9 @@ protected override bool EvaluateCanExecute(object parameter)
             }
 
             var targetInterface = _state.AllUserDeclarations.FindInterface(selection.Value);
-
-            var targetClass = _state.AllUserDeclarations.SingleOrDefault(d =>
-                d.DeclarationType == DeclarationType.ClassModule &&
-                d.QualifiedSelection.QualifiedName.Equals(selection.Value.QualifiedName));
+            
+            var targetClass = _state.DeclarationFinder.Members(selection.Value.QualifiedName)
+                .SingleOrDefault(declaration => declaration.DeclarationType == DeclarationType.ClassModule);
 
             return targetInterface != null && targetClass != null
                 && !_state.IsNewOrModified(targetInterface.QualifiedModuleName)

Rubberduck.Core/UnitTesting/ProjectTestExtensions.cs

@@ -1,7 +1,6 @@
 using System.Runtime.InteropServices;
 using System.Reflection;
 using System.IO;
-using System.Linq;
 using Rubberduck.VBEditor.SafeComWrappers.Abstract;
 
 namespace Rubberduck.UnitTesting