Make Theseus compilable out of the box again, update Tauri to 1.0.4

Changes made:
- migrate to Vite 3 (Svelte Kit errors out and forces you to migrate)
- bumped unplugin-icons to 0.14.7 (Vite 3 support)
- disable strict-peer-dependencies (changes needed in omorphia - unplugin-icons there requires Vite 2)
- bumped Tauri to 1.0.4 (finally stable!)
- removed useBootstrapper (removed in v1.0.0-rc.5)
- migrated from create_window to setup (removed in v1.0.0-rc.7)
- replaced %svelte% with %sveltekit% (renamed in SvelteKit 1.0.0-next.339)

Notes:
- Vite 3 exposes its dev server on port 5173.

theseus_gui/src-tauri/src/main.rs

@@ -13,8 +13,8 @@ fn main() {
 
     tauri::Builder::default()
         .invoke_handler(tauri::generate_handler![])
-        .create_window("main", WindowUrl::default(), |win, webview| {
-            let win = win
+        .setup(|app| {
+            let _win = WindowBuilder::new(app, "main", WindowUrl::default())
                 .title("Modrinth")
                 .resizable(true)
                 .decorations(true)
@@ -22,8 +22,9 @@ fn main() {
                 .inner_size(800.0, 550.0)
                 .min_inner_size(400.0, 200.0)
                 .skip_taskbar(false)
-                .fullscreen(false);
-            return (win, webview);
+                .fullscreen(false)
+                .build()?;
+            Ok(())
         })
         .menu(Menu::with_items([
             #[cfg(target_os = "macos")]