Hide connectors that need admin setup; they start turned off

A connector's enabled switch is now optional: unset means on when the
connector has the server settings it needs, so Google Drive, SharePoint
and Confluence start off until their OAuth settings are present, and an
admin's explicit switch always wins. Changing only the sharing mode no
longer switches a connector on.

Members only see connectors they can use. The catalog, Add Source tiles
and Add Tool leave out anything turned off or still needing setup, except
a connector a member already has a connection to, which stays listed as
turned off so it can be managed or removed.

tests/api/test_connector_oauth_security.py

@@ -9,6 +9,8 @@ from unittest.mock import MagicMock, patch
 import pytest
 from flask import Flask
 
+from tests.connectors.conftest import _oauth_connectors_configured  # noqa: F401,E402  (autouse)
+
 
 @pytest.fixture
 def app():

tests/api/test_connector_routes_happy.py

@@ -14,6 +14,8 @@ from unittest.mock import MagicMock, patch
 import pytest
 from flask import Flask
 
+from tests.connectors.conftest import _oauth_connectors_configured  # noqa: F401,E402  (autouse)
+
 
 @pytest.fixture
 def app():