feat(installer): rewrite install script

- 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.

worker/install/systemd/libretime-celery.service

@@ -2,9 +2,9 @@
 Description=LibreTime Worker Service
 
 [Service]
-Environment=LIBRETIME_LOG_FILEPATH=/var/log/libretime/worker.log
-Environment=LIBRETIME_CONFIG_FILEPATH=/etc/libretime/config.yml
-WorkingDirectory=/var/lib/libretime/worker
+Environment=LIBRETIME_LOG_FILEPATH=@@LOG_DIR@@/worker.log
+Environment=LIBRETIME_CONFIG_FILEPATH=@@CONFIG_FILEPATH@@
+WorkingDirectory=@@WORKING_DIR@@/worker
 
 ExecStart=/usr/bin/sh -c 'celery worker \
     --app=libretime_worker.tasks:worker \