feat(api): rename track type to library

Related to #1922

- rename library model fields

api/libretime_api/storage/serializers/__init__.py

@@ -1,3 +1,3 @@
 from .cloud_file import CloudFileSerializer
 from .file import FileSerializer
-from .track_type import TrackTypeSerializer
+from .library import LibrarySerializer

api/libretime_api/storage/serializers/library.py

@@ -0,0 +1,9 @@
+from rest_framework import serializers
+
+from ..models import Library
+
+
+class LibrarySerializer(serializers.HyperlinkedModelSerializer):
+    class Meta:
+        model = Library
+        fields = "__all__"

api/libretime_api/storage/serializers/track_type.py

@@ -1,9 +0,0 @@
-from rest_framework import serializers
-
-from ..models import TrackType
-
-
-class TrackTypeSerializer(serializers.HyperlinkedModelSerializer):
-    class Meta:
-        model = TrackType
-        fields = "__all__"