Update copy for new app provisioning

- change flashed message for adding members
- use the correct helper text for the app name input
- a few other updates to text in translations

templates/applications/new/step_1.html

@@ -28,7 +28,7 @@
           <div class="form-row">
             <div class="form-col form-col--two-thirds">
               {{ TextInput(form.name, optional=False) }}
-              {{ ('portfolios.applications.new.step_1_form_help_text.description' | translate | safe) }}
+              {{ ('portfolios.applications.new.step_1_form_help_text.name' | translate | safe) }}
             </div>
           </div>
           <hr>