make album column for tracks configurable

introduces new config variable `album_column`

fixes #267

src/library.rs

@@ -12,6 +12,7 @@ use serde::Serialize;
 use crate::album::Album;
 use crate::artist::Artist;
 use crate::config;
+use crate::config::Config;
 use crate::events::EventManager;
 use crate::playable::Playable;
 use crate::playlist::Playlist;
@@ -65,6 +66,10 @@ impl Library {
             .expect("could not readlock listview content")
     }
 
+    pub fn config(&self) -> &Config {
+        &self.spotify.cfg
+    }
+
     fn load_cache<T: DeserializeOwned>(&self, cache_path: PathBuf, store: Arc<RwLock<Vec<T>>>) {
         if let Ok(contents) = std::fs::read_to_string(&cache_path) {
             debug!("loading cache from {}", cache_path.display());