Restructure govuk-alerts endpoint to be internal

In response to: https://github.com/alphagov/notifications-api/pull/3305#pullrequestreview-726672421

Previously this was added among the public /v2 endpoints, but it's
only meant for internal use. While only the govuk-alerts app would
be able to access it, the location and /v2 URL suggested otherwise.
This restructures the endpoint so it resembles other internal ones.

app/__init__.py

@@ -133,6 +133,7 @@ def register_blueprint(application):
     from app.authentication.auth import (
         requires_admin_auth,
         requires_auth,
+        requires_govuk_alerts_auth,
         requires_no_auth,
     )
     from app.billing.rest import billing_blueprint
@@ -140,6 +141,7 @@ def register_blueprint(application):
     from app.complaint.complaint_rest import complaint_blueprint
     from app.email_branding.rest import email_branding_blueprint
     from app.events.rest import events as events_blueprint
+    from app.govuk_alerts.rest import govuk_alerts_blueprint
     from app.inbound_number.rest import inbound_number_blueprint
     from app.inbound_sms.rest import inbound_sms as inbound_sms_blueprint
     from app.job.rest import job_blueprint
@@ -269,18 +271,15 @@ def register_blueprint(application):
     broadcast_message_blueprint.before_request(requires_admin_auth)
     application.register_blueprint(broadcast_message_blueprint)
 
+    govuk_alerts_blueprint.before_request(requires_govuk_alerts_auth)
+    application.register_blueprint(govuk_alerts_blueprint)
+
 
 def register_v2_blueprints(application):
-    from app.authentication.auth import (
-        requires_auth,
-        requires_govuk_alerts_auth,
-    )
+    from app.authentication.auth import requires_auth
     from app.v2.broadcast.post_broadcast import (
         v2_broadcast_blueprint as post_broadcast,
     )
-    from app.v2.govuk_alerts.get_broadcasts import (
-        v2_govuk_alerts_blueprint as get_broadcasts,
-    )
     from app.v2.inbound_sms.get_inbound_sms import (
         v2_inbound_sms_blueprint as get_inbound_sms,
     )
@@ -321,9 +320,6 @@ def register_v2_blueprints(application):
     post_broadcast.before_request(requires_auth)
     application.register_blueprint(post_broadcast)
 
-    get_broadcasts.before_request(requires_govuk_alerts_auth)
-    application.register_blueprint(get_broadcasts)
-
 
 def init_app(app):
 

app/govuk_alerts/rest.py

@@ -1,11 +1,19 @@
-from flask import jsonify
+from flask import Blueprint, jsonify
 
 from app.dao.broadcast_message_dao import dao_get_all_broadcast_messages
+from app.errors import register_errors
 from app.utils import get_dt_string_or_none
-from app.v2.govuk_alerts import v2_govuk_alerts_blueprint
+
+govuk_alerts_blueprint = Blueprint(
+    "govuk-alerts",
+    __name__,
+    url_prefix='/govuk-alerts',
+)
+
+register_errors(govuk_alerts_blueprint)
 
 
-@v2_govuk_alerts_blueprint.route('')
+@govuk_alerts_blueprint.route('')
 def get_broadcasts():
     broadcasts = dao_get_all_broadcast_messages()
     broadcasts_dict = {"alerts": [{

app/v2/govuk_alerts/__init__.py

@@ -1,11 +0,0 @@
-from flask import Blueprint
-
-from app.v2.errors import register_errors
-
-v2_govuk_alerts_blueprint = Blueprint(
-    "v2_govuk-alerts_blueprint",
-    __name__,
-    url_prefix='/v2/govuk-alerts',
-)
-
-register_errors(v2_govuk_alerts_blueprint)