Always show live key, reword key labels

This is trying to resolve these confusions:

- that you’re in trial mode, which means you can’t have a live key yet (
  or you can but it wont work, which is what we used to have)
- what does simulate mean

The create key page is the right place to resolve these confusions
because it’s where users are actively reading.

This commit also removes the trial mode banner from API integration
page because this where users _aren’t_ actively reading. A whole bunch
of users weren’t seeing this banner at all.

The implementation of the disabled API key options is kinda clunky
because WTForms doesn’t have a native way of doing this.

¯\_(ツ)_/¯

tests/app/main/views/test_api_keys.py

@@ -21,7 +21,6 @@ def test_should_show_api_page(
         assert response.status_code == 200
         page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
         assert page.h1.string.strip() == 'API integration'
-        assert 'Your service is in trial mode' in page.find('div', {'class': 'banner-warning'}).text
         rows = page.find_all('details')
         assert len(rows) == 5
         for index, row in enumerate(rows):
@@ -201,10 +200,7 @@ def test_cant_create_normal_api_key_in_trial_mode(
             'key_type': 'normal'
         }
     )
-    assert response.status_code == 200
-    page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
-    assert page.find('span', {'class': 'error-message'}).text.strip() == 'Not a valid choice'
-
+    assert response.status_code == 400
     mock_post.assert_not_called()