Removed links to add_template_by_type_endpoint

The endpoint was removed, but was still linked to in a couple of
places. Some old links were no longer needed, so have been removed.

We do still need a link to `add_template_by_type` on the 'Choose reply'
page - this page is used to allow to let someone pick a template to
reply to inbound SMS with. Since the link only appears if they have no
SMS templates, we now link to `.choose_template` with the templates and
folders form already opened at the option to add a template.

tests/app/main/views/test_templates.py

@@ -196,6 +196,21 @@ def test_should_show_page_for_choosing_a_template(
     mock_get_template_folders.assert_called_once_with(SERVICE_ONE_ID)
 
 
+def test_choose_template_can_pass_through_an_initial_state_to_templates_and_folders_selection_form(
+    client_request,
+    mock_get_template_folders,
+    mock_get_service_templates,
+):
+    page = client_request.get(
+        'main.choose_template',
+        service_id=SERVICE_ONE_ID,
+        initial_state='add-new-template'
+    )
+
+    templates_and_folders_form = page.find('form')
+    assert templates_and_folders_form['data-prev-state'] == 'add-new-template'
+
+
 def test_should_not_show_template_nav_if_only_one_type_of_template(
     client_request,
     mock_get_template_folders,