Store user settings/data on the server and multi user support (#2160)

* wip per user data

* Rename, hide menu

* better error
rework default user

* store pretty

* Add userdata endpoints
Change nodetemplates to userdata

* add multi user message

* make normal arg

* Fix tests

* Ignore user dir

* user tests

* Changed to default to browser storage and add server-storage arg

* fix crash on empty templates

* fix settings added before load

* ignore parse errors