Extract formatters into their own module

We have lots of functions for converting various types of data into
strings to be displayed to the user somewhere.

This commit collects all these functions into their own module, rather
than having them cluttering up `app/__init__.py` or buried amongst
various other things that have ended up in `app/utils.py`.

tests/app/main/views/uploads/test_upload_contact_list.py

@@ -6,7 +6,7 @@ import pytest
 from flask import url_for
 from freezegun import freeze_time
 
-from app.utils import normalize_spaces
+from app.formatters import normalize_spaces
 from tests.conftest import SERVICE_ONE_ID
 
 

tests/app/main/views/uploads/test_upload_hub.py

@@ -4,7 +4,7 @@ import pytest
 from flask import url_for
 from freezegun import freeze_time
 
-from app.utils import normalize_spaces
+from app.formatters import normalize_spaces
 from tests.conftest import (
     SERVICE_ONE_ID,
     create_active_caseworking_user,

tests/app/main/views/uploads/test_upload_letter.py

@@ -5,8 +5,8 @@ from botocore.exceptions import ClientError
 from flask import make_response, url_for
 from requests import RequestException
 
+from app.formatters import normalize_spaces
 from app.s3_client.s3_letter_upload_client import LetterMetadata
-from app.utils import normalize_spaces
 from tests.conftest import SERVICE_ONE_ID