Add tracks editor UI

data/ui/tracks_editor_track_row.blp

@@ -0,0 +1,25 @@
+using Gtk 4.0;
+using Adw 1;
+
+template $MusicusTracksEditorTrackRow: Adw.ActionRow {
+  title: _("Select parts");
+  activatable: true;
+  activated => $select_parts() swapped;
+
+  [prefix]
+  Gtk.Box select_parts_box {
+    Gtk.Image {
+      icon-name: "document-edit-symbolic";
+    }
+  }
+
+  Gtk.Button {
+    icon-name: "user-trash-symbolic";
+    valign: center;
+    clicked => $remove() swapped;
+
+    styles [
+      "flat"
+    ]
+  }
+}