feat: move storage path setting to configuration file

- change default storage path to /srv/libretime
- remove music dirs table
- use /tmp for testing storage
- storage dir should always have a trailing slash

legacy/tests/config/config.yml

@@ -3,9 +3,5 @@ general:
   public_url: http://localhost
   api_key: H2NRICX6CM8F50CU123C
 
-database:
-  host: localhost
-  port: 5432
-  name: libretime_test
-  user: libretime
-  password: libretime
+storage:
+  path: /tmp