feat: Enhance playlist management and GUI logic

- Improved playlist item fetching by adding robust pagination and low-level request hooks for better testing and flexibility.
- Refactored track ID extraction logic into reusable helpers for clarity.
- Improved initialization for dialog components to avoid circular dependencies in the GUI.
- Added new unit tests to validate playlist operations, including track addition/removal and API integration.
- Updated metadata functions to simplify dictionary access using `.get` for better readability.
- Ensured PySide6 system dependencies are installed in GitHub Actions to address CI compatibility issues.
- Streamlined UI package initialization to improve modularity and robustness of imports.

tidal_dl_ng/helper/metadata_utils.py

@@ -14,10 +14,10 @@ def _convert_list_to_str(value: list | tuple) -> str:
 
 def _convert_dict_to_str(value: dict) -> str:
     """Extract meaningful string from dict."""
-    if "name" in value and value["name"]:
+    if value.get("name"):
         return str(value["name"])
     for k in ("label", "title", "genre", "name"):
-        if k in value and value[k]:
+        if value.get(k):
             return str(value[k])
     with suppress(Exception):
         vals = [str(v) for v in value.values() if v is not None]
@@ -177,7 +177,7 @@ def _extract_name_from_item(item: object) -> str | None:
     if isinstance(item, dict):
         # Try common name keys
         for k in ("name", "artist", "person"):
-            if k in item and item[k]:
+            if item.get(k):
                 return str(item[k])
         return None
     # Try object attributes