Add example which runs `react-server` conditioned environment with module runner on browser

[hi-ogawa]

• this is a variant of packages/plugin-rsc/examples/no-ssr and packages/plugin-rsc/examples/browser-mode
• runs rsc environment of packages/plugin-rsc/examples/no-ssr on browser via module runner like packages/plugin-rsc/examples/browser-mode/src/framework/load-client-dev.tsx
• it should be able to use import rsc from "@vitejs/plugin-rsc" like examples/no-ssr. It shouldn't use vitePluginRscMinimal like browser-mode.
• add examples/browser-mode2

Related https://bsky.app/profile/danabra.mov/post/3m3iei53v3c2k