Remove redundant hidden H3s

This commit replaces the H3s which only repeated information with some
hidden text that will make it read nicer for screenreaders.

tests/app/main/views/test_index.py

@@ -34,10 +34,7 @@ def test_non_logged_in_user_can_see_homepage(
 
     assert normalize_spaces(page.select_one('#whos-using-notify').text) == (
         'Who’s using GOV.UK Notify '
-        'Organisations '
-        '111 organisations '
-        'Services '
-        '9,999 services '
+        'There are 111 organisations and 9,999 services using Notify. '
         'See the list of services and organisations.'
     )
     assert page.select_one('#whos-using-notify a')['href'] == url_for(

tests/app/main/views/test_performance.py

@@ -116,7 +116,6 @@ def test_should_render_performance_page(
         'Performance data '
         ''
         'Messages sent since May 2016 '
-        'Total messages '
         '1.8 billion total '
         '1.1 billion emails '
         '987.7 million text messages '
@@ -134,7 +133,6 @@ def test_should_render_performance_page(
         'Only showing the last 7 days '
         ''
         'Messages sent within 10 seconds '
-        'Average '
         '96.8% on average '
         'Messages sent within 10 seconds '
         'Date Percentage '
@@ -148,8 +146,7 @@ def test_should_render_performance_page(
         'Only showing the last 7 days '
         ''
         'Organisations using Notify '
-        'Organisations 111 organisations '
-        'Services 9,999 services '
+        'There are 111 organisations and 9,999 services using Notify. '
         'Organisations using Notify '
         'Organisation Number of live services '
         'Department of Examples and Patterns 2 '