WIP: Use main email for sso

[HugoPoi]

• [x] Rebase on top of #48
• [x] Add an action for moving an account based on the code of change-url script
• [x] Remove change-url script because it will be a non-sense
• [x] Add documentation

[HugoPoi]

For documentation

I have added some information in the actions.json but we need to add a link somewhere to the actions page because it's still a beta feature. We may need to add something in the README ?

[Josue-T]

I have added some information in the actions.json but we need to add a link somewhere to the actions page because it's still a beta feature. We may need to add something in the README ?

Yes, please update the README. Mainly theses sections:

• https://github.com/YunoHost-Apps/seafile_ynh#change-url
• https://github.com/YunoHost-Apps/seafile_ynh#multi-users-support