Add Windows support to cache

Author: brefra

plugwise_usb/helpers/cache.py

@@ -59,7 +59,10 @@ async def initialize_cache(self, create_root_folder: bool = False) -> None:
             cache_dir = self._get_writable_os_dir()
         await makedirs(cache_dir, exist_ok=True)
         self._cache_path = cache_dir
-        self._cache_file = f"{cache_dir}/{self._file_name}"
+        if os_name == "nt":
+            self._cache_file = f"{cache_dir}\\{self._file_name}"
+        else:
+            self._cache_file = f"{cache_dir}/{self._file_name}"
         self._cache_file_exists = await ospath.exists(self._cache_file)
         self._initialized = True
         _LOGGER.debug("Start using network cache file: %s", self._cache_file)