add silence removal using pydub and multithreading

+ fix favorites endpoint returning items less than limit
+ add endpoint to remove get silence padding
+ add 'the ulitimate' and 'compilation' to compilation album filters
+ misc

app/utils/threading.py

@@ -10,3 +10,25 @@ def background(func):
         threading.Thread(target=func, args=a, kwargs=kw).start()
 
     return background_func
+
+
+class ThreadWithReturnValue(threading.Thread):
+    """
+    A thread class that returns a value on join.
+
+    Credit: https://stackoverflow.com/a/6894023
+    """
+
+    def __init__(
+        self, group=None, target=None, name=None, args=(), kwargs={}, Verbose=None
+    ):
+        threading.Thread.__init__(self, group, target, name, args, kwargs)
+        self._return = None
+
+    def run(self):
+        if self._target is not None:
+            self._return = self._target(*self._args, **self._kwargs)
+
+    def join(self, *args):
+        threading.Thread.join(self, *args)
+        return self._return