oauth_google_login: apply a 10 seconds timeout when connecting to google server

In case of network problems, the http requests made to google during
login may take too long and cause global unavailability of the ERP5
instance.

Today we saw in long request logs:

    2023-05-29 07:10:35,662 - Thread 140596157511424: Started on 1685336511.6; Running for 524.1 secs; Same.

oauth2client does not expose an API to set a timeout, but it allows
passing a custom http instance where we can set a timeout.

bt5/erp5_oauth_google_login/ExtensionTemplateItem/portal_components/extension.erp5.GoogleLoginUtility.py

 import json
 import oauth2client.client
+import oauth2client.transport
 from Products.ERP5Security.ERP5ExternalOauth2ExtractionPlugin import getGoogleUserEntry
 from zExceptions import Unauthorized
 
 
 SCOPE_LIST = ['https://www.googleapis.com/auth/userinfo.profile',
               'https://www.googleapis.com/auth/userinfo.email']
+# Default timeout (in seconds) for the HTTP request made to google servers to
+# exchange the authorization code for a token.
+DEFAULT_HTTP_TIMEOUT = 10
 
 
 def _getGoogleClientIdAndSecretKey(portal, reference="default"):
@@ -33,7 +37,7 @@ def redirectToGoogleLoginPage(self):
     include_granted_scopes="true")
   self.REQUEST.RESPONSE.redirect(flow.step1_get_authorize_url())
 
-def getAccessTokenFromCode(self, code, redirect_uri):
+def getAccessTokenFromCode(self, code, redirect_uri, timeout=DEFAULT_HTTP_TIMEOUT):
   client_id, secret_key = _getGoogleClientIdAndSecretKey(self.getPortalObject())
   flow = oauth2client.client.OAuth2WebServerFlow(
     client_id=client_id,
@@ -42,7 +46,9 @@ def getAccessTokenFromCode(self, code, redirect_uri):
     redirect_uri=redirect_uri,
     access_type="offline",
     include_granted_scopes="true")
-  credential = flow.step2_exchange(code)
+  credential = flow.step2_exchange(
+    code,
+    http=oauth2client.transport.get_http_object(timeout=timeout))
   credential_data = json.loads(credential.to_json())
   return credential_data