Rename OAuth2 servlet path from /oauth2/authorization to /oauth2/authorize

For the Mobile app to be able to distinguish a Nuxeo instance >= 9.2 from an earlier version in terms of OAuth2 authorization (without being connected).

If /oauth2/authorize is available it means that the Nuxeo version is >= 9.2 and the recent OAuth2 authorization flow is available, else fall back on the Nuxeo login token.