feat(dashboard,admin-sdk,admin-shared,admin-vite-plugin): Add support for UI extensions (#7383)

* intial work

* update lock

* add routes and fix HMR of configs

* cleanup

* rm imports

* rm debug from plugin

* address feedback

* address feedback

packages/admin-next/admin-shared/tsup.config.cjs

@@ -0,0 +1,8 @@
+import { defineConfig } from "tsup"
+
+export default defineConfig({
+  entry: ["./src/index.ts"],
+  format: ["cjs", "esm"],
+  dts: true,
+  clean: true,
+})