ui: finish the library info dialogs and add playlist info

Sort names and titles are only shown when they differ from the regular
name, so artists without a distinct sort name no longer repeat the name.

Track info uses plural labels for both the artists and their sort name
when the track has more than one artist, and singular labels otherwise.
Added and last played sit together in album info.

Playlists gain an Info dialog with owner, sharing, song count, length,
creation and update dates. Owner and the public flag are synced from
getPlaylists, so a schema migration adds both columns.

app/src/main/res/values/strings.xml

@@ -198,6 +198,7 @@
     <string name="info_channels">Channels</string>
     <string name="info_close">Close</string>
     <string name="info_artists">Artists</string>
+    <string name="info_artists_sort">Artists sort</string>
     <string name="info_album_artists">Album artists</string>
     <string name="info_album_artist_sort">Album artist sort</string>
     <string name="info_sort_title">Sort title</string>
@@ -208,6 +209,11 @@
     <string name="info_plays">Plays</string>
     <string name="info_last_played">Last played</string>
     <string name="info_added">Added</string>
+    <string name="info_created">Created</string>
+    <string name="info_updated">Updated</string>
+    <string name="info_owner">Owner</string>
+    <string name="info_shared">Shared</string>
+    <string name="info_length">Length</string>
     <string name="info_downloaded_count">%1$d of %2$d</string>
 
     <string name="disc_header">Disc %1$d</string>