Cancel button for diff notes

Added "cancel" comment button for inline diff notes for commits

app/assets/javascripts/notes.js

@@ -982,6 +982,10 @@ export default class Notes {
     // DiffNote
     form.find('#note_position').val(dataHolder.attr('data-position'));
+    form
+      .find('.js-close-discussion-note-form')
+      .show()
+      .removeClass('hide');
     form.find('.js-note-target-close').remove();
     form.find('.js-note-new-discussion').remove();
     this.setupNoteForm(form);

app/views/shared/notes/_form.html.haml

@@ -39,3 +39,6 @@
       = render partial: 'shared/notes/comment_button'
       = yield(:note_actions)
+
+      %a.btn.btn-cancel.js-close-discussion-note-form.hide{ role: "button", data: {cancel_text: "Cancel" } }
+        Cancel