GTNPORTAL-3450: Impossible to upload file in Content Explorer when tmpdir does not exist

Fix description:
- When uploading a file, check if tmpdir exists. If not, create it
GTNPORTAL-3500 Remove the unreality testcase in multi-threading
GTNPORTAL-3486 Redirect to /sso instead of /login when SSO is enabled
GTNPORTAL-3490 Add missing i18n keys in Services Management gadget (3.7.x)