- add possibility to grant an external user.
- route /api/users/{id} added (rate limited for security)
- security: start route limitation for external users
ex: they must not browse /api/users/{id} nor addressbook
- SMTP has a mock to enable end to end test and validate the whole path
(via OXICLOUD_SMTP_MOCK)
- add email normalisation ( including punicode)
- api to share to external user