add method and route to search across tracks, albums and artists.

+ break models into separate files
+ same for the utils and setup

app/utils/wintools.py

@@ -0,0 +1,16 @@
+import platform
+
+
+# TODO: Check is_windows on app start in settings.py
+def is_windows():
+    """
+    Returns True if the OS is Windows.
+    """
+    return platform.system() == "Windows"
+
+
+def win_replace_slash(path: str):
+    if is_windows():
+        return path.replace("\\", "/").replace("//", "/")
+
+    return path