fix forwarder icon passing in the wrong size, fix github zip detection / extraction, add back url in json

- i was passing the wrong size for icon, so it always failed to load.
- i didnt realise zips can have many content types, so now i search for the name "zip" which works well.
- extracting a zip will fail if the files are all in the root, ie, no folder, and the subfolders do
  not already exist.
- fix misspelling of download.

sphaira/include/ui/menus/ghdl.hpp

@@ -17,8 +17,10 @@ struct AssetEntry {
 
 struct Entry {
     fs::FsPath json_path;
+    std::string url;
     std::string owner;
     std::string repo;
+    std::string tag;
     std::string pre_install_message;
     std::string post_install_message;
     std::vector<AssetEntry> assets;