Fix the title of the tasks that search for duplicates in extract method

I've corrected capitalization of the text and move it to RefactoringBundle.

platform/lang-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodHelper.java

@@ -61,7 +61,7 @@ public class ExtractMethodHelper {
       return;
     }
     final Project project = callElement.getProject();
-    ProgressManager.getInstance().run(new Task.Backgroundable(project, "Searching for duplicates...", true) {
+    ProgressManager.getInstance().run(new Task.Backgroundable(project, RefactoringBundle.message("searching.for.duplicates"), true) {
       public void run(@NotNull ProgressIndicator indicator) {
         if (myProject == null || myProject.isDisposed()) return;
         final List<SimpleMatch> duplicates = ApplicationManager.getApplication().runReadAction(new Computable<List<SimpleMatch>>() {
@@ -100,7 +100,7 @@ public class ExtractMethodHelper {
       return ProgressManager.getInstance().runProcessWithProgressSynchronously(
         (ThrowableComputable<List<SimpleMatch>, RuntimeException>)() -> {
           return ReadAction.compute(() -> finder.findDuplicates(searchScopes, generatedMethod));
-        }, "Searching for duplicates...", true, project);
+        }, RefactoringBundle.message("searching.for.duplicates"), true, project);
     }
     catch (ProcessCanceledException e) {
       return Collections.emptyList();

platform/platform-resources-en/src/messages/RefactoringBundle.properties

@@ -565,6 +565,7 @@ move.directory.0=Move directory {0}
 move.files.to.directory.label=To directory:
 the.file.will.be.moved.to.this.directory=File will be moved to this directory
 searching.for.variables=Searching for variables
+searching.for.duplicates=Searching for Duplicates...
 no.usages.can.be.replaced=No usages of {0} \ncan be replaced with usages of {1}
 turn.refs.to.super.command=Replacing usages of {0} with {1}
 references.to.0.to.be.replaced.with.references.to.1=References to ''{0}'' to be replaced with references to ''{1}''