refactor(Track): Use defaultdict with a dict factory for data property

This is so both internal code and service code can save data to sub-keys without the parent keys needing to exist.

This also fixes a bug introduced in v3.3.3 where it will fail to download tracks without the "hls" key in the data property. This can happen when manually making Audio tracks using the HLS descriptor, and not putting any of the hls data the HLS class sets in to_tracks().

devine/core/tracks/track.py

@@ -4,6 +4,7 @@
 import re
 import shutil
 import subprocess
+from collections import defaultdict
 from copy import copy
 from enum import Enum
 from functools import partial
@@ -42,7 +43,7 @@ def __init__(
         drm: Optional[Iterable[DRM_T]] = None,
         edition: Optional[str] = None,
         downloader: Optional[Callable] = None,
-        data: Optional[dict] = None,
+        data: Optional[Union[dict, defaultdict]] = None,
         id_: Optional[str] = None,
     ) -> None:
         if not isinstance(url, (str, list)):
@@ -63,8 +64,8 @@ def __init__(
             raise TypeError(f"Expected edition to be a {str}, not {type(edition)}")
         if not isinstance(downloader, (Callable, type(None))):
             raise TypeError(f"Expected downloader to be a {Callable}, not {type(downloader)}")
-        if not isinstance(data, (dict, type(None))):
-            raise TypeError(f"Expected data to be a {dict}, not {type(data)}")
+        if not isinstance(data, (dict, defaultdict, type(None))):
+            raise TypeError(f"Expected data to be a {dict} or {defaultdict}, not {type(data)}")
 
         invalid_urls = ", ".join(set(type(x) for x in url if not isinstance(x, str)))
         if invalid_urls:
@@ -93,7 +94,7 @@ def __init__(
         self.drm = drm
         self.edition: str = edition
         self.downloader = downloader
-        self.data = data or {}
+        self.data = defaultdict(dict, **(data or {}))
 
         if self.name is None:
             lang = Language.get(self.language)