Move data transformation into the form

Follows what we’re doing with the folders stuff. Avoids having too many
very straightforward methods on the model. Especially when the data they
need is only used by the form. So it’s better to encapsulate the logic
in the form.

tests/app/main/test_create_api_key_form.py

@@ -5,10 +5,12 @@ from app.main.forms import CreateKeyForm
 
 
 def test_return_validation_error_when_key_name_exists(client):
-    def _get_names():
-        return ['some key', 'another key']
+    _existing_keys = [
+        {'name': 'some key'},
+        {'name': 'another key'},
+    ]
 
-    form = CreateKeyForm(_get_names(),
+    form = CreateKeyForm(_existing_keys,
                          formdata=MultiDict([('key_name', 'Some key')]))
     form.key_type.choices = [('a', 'a'), ('b', 'b')]
     form.validate()