Allow users of the API to search templates by ID

For someone who has retrieved a template ID from their system the only
way to find it in Notify is:
- hack the URL
- click through every template, visually inspecting the ID shown on the
  page until you find the right one

Neither of these is ideal.

This commit adds searching by ID, for those services who have an API
integration. This means we don’t need to confuse teams who aren’t using
the API by talking about IDs.

This is similar to how we let these teams search for notifications by
reference[1]

1. https://github.com/alphagov/notifications-admin/pull/3223/files

tests/app/main/views/test_template_folders.py

@@ -375,6 +375,7 @@ def test_should_show_templates_folder_page(
     client_request,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     service_one,
     mocker,
     expected_title_tag,
@@ -477,6 +478,71 @@ def test_should_show_templates_folder_page(
     mock_get_service_templates.assert_called_once_with(SERVICE_ONE_ID)
 
 
+def test_template_id_is_searchable_for_services_with_api_keys(
+    client_request,
+    mock_get_template_folders,
+    mock_has_no_jobs,
+    mock_get_api_keys,
+    service_one,
+    mocker,
+
+):
+    mock_get_template_folders.return_value = [
+        _folder('folder one', PARENT_FOLDER_ID),
+    ]
+    template_1 = _template('sms', 'template one')
+    template_2 = _template('sms', 'template two', parent=PARENT_FOLDER_ID)
+    mocker.patch(
+        'app.service_api_client.get_service_templates',
+        return_value={'data': [
+            template_1,
+            template_2,
+        ]}
+    )
+
+    page = client_request.get(
+        'main.choose_template',
+        service_id=SERVICE_ONE_ID,
+        _test_page_title=False,
+    )
+
+    assert [
+        normalize_spaces(item.text)
+        for item in page.select(
+            # Elements which the live search will filter by
+            '.template-list-item .live-search-relevant'
+        )
+    ] == [
+        'folder one',
+        f'{template_2["id"]} template two',
+        f'{template_1["id"]} template one',
+    ]
+
+    assert [
+        normalize_spaces(item.text)
+        for item in page.select(
+            # Elements the user will see when first loading the page
+            '.template-list-item:not(.template-list-item-hidden-by-default)'
+        )
+    ] == [
+        'folder one folder one 1 template',
+        f'template one {template_1["id"]} template one Text message template',
+    ]
+
+    assert [
+        normalize_spaces(item.text)
+        for item in page.select(
+            # Text which should be hidden from all users
+            r'#template-list .govuk-\!-display-none'
+        )
+    ] == [
+        template_2["id"],
+        template_1["id"],
+    ]
+
+    mock_get_api_keys.assert_called_once_with(SERVICE_ONE_ID)
+
+
 def test_can_create_email_template_with_parent_folder(
         client_request,
         mock_create_service_template
@@ -968,6 +1034,7 @@ def test_should_show_checkboxes_for_selecting_templates(
     mock_get_service_templates,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     user,
 ):
     client_request.login(user)
@@ -1003,6 +1070,7 @@ def test_should_not_show_radios_and_buttons_for_move_destination_if_incorrect_pe
     mock_get_service_templates,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     user,
 ):
     client_request.login(user)
@@ -1027,6 +1095,7 @@ def test_should_show_radios_and_buttons_for_move_destination_if_correct_permissi
     mock_get_service_templates,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     fake_uuid,
     active_user_with_permissions
 ):
@@ -1070,6 +1139,7 @@ def test_move_to_shouldnt_select_a_folder_by_default(
     mock_get_service_templates,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     fake_uuid,
     active_user_with_permissions
 ):
@@ -1168,6 +1238,7 @@ def test_move_folder_form_shows_current_folder_hint_when_in_a_folder(
     service_one,
     mock_get_service_templates,
     mock_get_template_folders,
+    mock_get_no_api_keys,
 ):
     mock_get_template_folders.return_value = [
         _folder('parent_folder', PARENT_FOLDER_ID, None),
@@ -1195,6 +1266,7 @@ def test_move_folder_form_does_not_show_current_folder_hint_at_the_top_level(
     service_one,
     mock_get_service_templates,
     mock_get_template_folders,
+    mock_get_no_api_keys,
 ):
     mock_get_template_folders.return_value = [
         _folder('parent_folder', PARENT_FOLDER_ID, None),
@@ -1306,6 +1378,7 @@ def test_no_action_if_user_fills_in_ambiguous_fields(
     mock_get_template_folders,
     mock_move_to_template_folder,
     mock_create_template_folder,
+    mock_get_no_api_keys,
     data,
 ):
     service_one['permissions'] += ['letter']
@@ -1434,6 +1507,7 @@ def test_radio_button_with_no_value_shows_custom_error_message(
     mock_get_template_folders,
     mock_move_to_template_folder,
     mock_create_template_folder,
+    mock_get_no_api_keys,
 ):
     page = client_request.post(
         'main.choose_template',
@@ -1473,6 +1547,7 @@ def test_show_custom_error_message(
         mock_get_template_folders,
         mock_move_to_template_folder,
         mock_create_template_folder,
+        mock_get_no_api_keys,
         data,
         error_msg,
 ):
@@ -1604,6 +1679,7 @@ def test_should_filter_templates_folder_page_based_on_user_permissions(
     client_request,
     mock_get_template_folders,
     mock_has_no_jobs,
+    mock_get_no_api_keys,
     service_one,
     mocker,
     active_user_with_permissions,