Issue #3415232: Get rid of ENV vars in LFM Service

Replaced env vars with injected config factory.

Assuming the module (and drush) are installed, use config:edit to add new setting:

php docroot/vendor/bin/drush config:edit musica.settings

For example:

lastfm_api_endpoint: https://ws.audioscrobbler.com/2.0/
lastfm_api_key: [YOUR_LASTFM_KEY]
lastfm_api_secret: [YOUR_LASTFM_SECRET]

After editing settings, answer (yes) to prompt asking to import "configuration changes".

Screenshot of drush command and prompt:

Install config schema updated as well.