Move the parent <-> children relationship to Mergin Maps server

[saberraz]

Currently, when I want to see changes, I need to re-run the tool to sync the changes between parents <-> children. It would be good to migrate this configuration to the server so that changes automatically propagated across MM projects on the server side and users do not need to re-run the tool. In QGIS plugin, we can have configurations, to turn on/off the sync between parent <-> child or link/unlink the projects.

[wojtek19022]

Hi Saber! I actually developed a docker compose to set up work-packages extension once and it is refreshing itself without my interaction. When the project that i'm working on will be finished i can upload it or we can discuss how it'd be implemented