### Description
This ensures that when the LibreTime interface is not used for a long
time, we still have the task manager run essential tasks for the
schedule.
Related to #2670
BREAKING CHANGE: The `libretime-celery` python package and service was renamed to `libretime-worker`. Make sure to remove the old python package and service.
BREAKING CHANGE: The default `www-data` user has been replaced by a dedicated `libretime` user to run the services. Be sure to change the ownership of the libretime files.
- remove unused root packages.ini
- write config to yaml file
- allow to set public_url during install
- force icecast start right after package install
- move config file in place at the end of installation
BREAKING CHANGE: The bash installer has been rewritten, the flags and
options changed, please run `./install --help` to get more details.
BREAKING CHANGE: The worker `RMQ_CONFIG_FILE` environement variable has
been renamed to `LIBRETIME_CONFIG_FILEPATH`. In addition the systemd
working directory for the worker has changed from `/srv/airtime` to
`/var/lib/libretime/worker`.