Refactor TorrentInfoEndpoint to fix JSON encoding issue

The code changes in this commit refactor the TorrentInfoEndpoint class in order to fix a JSON encoding issue. The previous implementation used json.dumps, which garbled binary data in the 'pieces' field. This commit removes that line of code and ensures that the GUI does not rely on this field.

src/tribler/core/components/libtorrent/restapi/torrentinfo_endpoint.py

@@ -154,9 +154,6 @@ async def get_torrent_info(self, request):
         # Check if the torrent is already in the downloads
         encoded_metainfo = deepcopy(metainfo)
 
-        # FIXME: json.dumps garbles binary data that is used by the 'pieces' field
-        # However, this is fine as long as the GUI does not use this field.
-        encoded_metainfo[b'info'][b'pieces'] = hexlify(encoded_metainfo[b'info'][b'pieces']).encode('utf-8')
         encoded_metainfo = hexlify(json.dumps(recursive_unicode(
             encoded_metainfo, ignore_errors=True), ensure_ascii=False).encode('utf-8'))
         return RESTResponse({"metainfo": encoded_metainfo,