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/web/tsconfig.json

@@ -0,0 +1,12 @@
+{
+  "extends": "../../../tsconfig.json",
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "lib",
+    "moduleResolution": "Bundler",
+    "types": ["affine__env"],
+    "rootDir": "./src"
+  },
+  "include": ["./src"],
+  "references": [{ "path": "../core" }]
+}