[Feature] Mock Nextcloud backend behavior

[chadek]

Project such as /e/ OS maintained by Murena rely on Nextcloud which is the main reason retaining me to move to an other more efficient solution such as Opencloud.

It would be wonderfull if I could just setup an OpenCloud back-end server and configure it as a "nextcloud" account on my phone. So basically it means providing compatibility with nextcloud clients (which would probably imply loosing performance)

An other solution would be to ask Murena to start looking at this project and developing clients to sync files, contact, agenda etc...