Update CreateServiceForm with new fields

Changes its StringField to GovukTextInputField.

Includes changes to templates that use this form
and associated tests.

app/main/forms.py

@@ -1131,7 +1131,7 @@ class OrganisationDomainsForm(StripWhitespaceForm):
 
 
 class CreateServiceForm(StripWhitespaceForm):
-    name = StringField(
+    name = GovukTextInputField(
         "What’s your service called?",
         validators=[
             DataRequired(message='Cannot be empty'),

app/templates/views/add-service-local.html

@@ -26,7 +26,7 @@
 
     {% call form_wrapper() %}
 
-      {{ textbox(form.name, hint="You can change this later") }}
+      {{ form.name(param_extensions={"hint": {"text": "You can change this later"}}) }}
 
       {{ page_footer('Add service') }}
 

app/templates/views/add-service.html

@@ -1,6 +1,5 @@
 {% extends "withoutnav_template.html" %}
 {% from "components/radios.html" import radios %}
-{% from "components/textbox.html" import textbox %}
 {% from "components/page-header.html" import page_header %}
 {% from "components/page-footer.html" import page_footer %}
 {% from "components/form.html" import form_wrapper %}
@@ -18,7 +17,7 @@
 
     {% call form_wrapper() %}
 
-      {{ textbox(form.name, hint="You can change this later") }}
+      {{ form.name(param_extensions={"hint": {"text": "You can change this later"}}) }}
 
       {% if not default_organisation_type %}
         {{ radios(form.organisation_type) }}