refactor(core): split web entry from core (#6082)

This pr is trying to split `web` and `electron` entries from `core`. It allows more platform-related optimization to be addressed in each entry.
We should remove all browser/electron only codes from `core` eventually, this is the very first step for that.

packages/frontend/templates/build-edgeless.mjs

@@ -306,9 +306,5 @@ export const builtInTemplates = {
   });
 };
 
-async function main() {
-  const templatesInGroup = await parseSnapshot();
-  await buildScript(templatesInGroup);
-}
-
-main();
+const templatesInGroup = await parseSnapshot();
+await buildScript(templatesInGroup);