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.

installer/config.yml

@@ -0,0 +1,55 @@
+# See https://libretime.org/docs/admin-manual/setup/configuration/
+
+general:
+  # The public url, this field is REQUIRED
+  public_url:
+  # The internal API authentication key, this field is REQUIRED
+  api_key:
+
+  # How many hours ahead Playout should cache scheduled media files, default is 1
+  cache_ahead_hours: 1
+
+  # Authentication adaptor to use for the legacy service, default is local
+  # Specify a class like LibreTime_Auth_Adaptor_FreeIpa to replace the built-in adaptor
+  auth: local
+
+database:
+  # The hostname of the PostgreSQL server, default is localhost
+  host: localhost
+  # The port of the PostgreSQL server, default is 5432
+  port: 5432
+  # The name of the PostgreSQL database, default is libretime
+  name: libretime
+  # The username of the PostgreSQL user, default is libretime
+  user: libretime
+  # The password of the PostgreSQL user, default is libretime
+  password: libretime
+
+rabbitmq:
+  # The hostname of the RabbitMQ server, default is localhost
+  host: localhost
+  # The port of the RabbitMQ server, default is 5672
+  port: 5672
+  # The virtual host of RabbitMQ server, default is /libretime
+  vhost: /libretime
+  # The username of the RabbitMQ user, default is libretime
+  user: libretime
+  # The password of the RabbitMQ user, default is libretime
+  password: libretime
+
+playout:
+  # Liquidsoap connection host, default is localhost
+  liquidsoap_host: localhost
+  # Liquidsoap connection port, default is 1234
+  liquidsoap_port: 1234
+
+  # The format for recordings, allowed values ogg,mp3, default is ogg
+  record_file_format: ogg
+  # The bitrate for recordings, default is 256
+  record_bitrate: 256
+  # The samplerate for recordings, default is 256
+  record_samplerate: 44100
+  # The number of channels for recordings, default is 2
+  record_channels: 2
+  # The sample size for recordings, default is 16
+  record_sample_size: 16