prefect: add dburl to worker
prefect: use same state directory
prefect: fix worker environment
prefect: create user
prefect: use datadir for sqlite url
prefect: make datadir writable
prefect: don't protect home
prefect fix sqlite url
prefect: fix state directory
prefect: user should not be systemuser
prefect: set to normal user
add prefect to systempackages
try user with same name
prefect use prefect_home
do not set database url
revert to dynamic user
prefect: add tests
prefect: fix port to string
