Async downloader, better Proton support (#183)

* feat: async downloader + other fixes

* feat: windows command parsing + use library path for install path

* feat: better proton support

* feat: style fixes and store button now uses in-app

* feat: emulator rename + umu emulator fix

* feat: bring process creation inline with docs

* fix: clippy

desktop/src-tauri/process/src/parser.rs

@@ -43,8 +43,8 @@ impl ParsedCommand {
         v.extend(self.env);
         v.extend_one(self.command);
         v.extend(self.args);
-        v.join(" ")
+        shell_words::join(v)
     }
 }
 
-pub struct LaunchParameters(pub String, pub PathBuf);
+pub struct LaunchParameters(pub ParsedCommand, pub PathBuf);