FRP: Add default `settings` pages

[Majorfi]

What is your proposal 🚀

Add a default pages used to be able to overwrite some environment variables and/or specific endpoints.

What does this solve ? 🛠

The motivation is simple: make our products resilients. What if, tomorrow, IPFS is still there with our project, but the API is down ? Now way to use the build for some projects. Being able to change the RPC, to change yDaemon endpoints etc. is a big win to avoid that and to allow users to use their localhost endpoints

More 🔎

N/A

[ai-slave]

Just checking if work that has been done on this task doesn't interfere with these:

[0xBasically]

Yes please this would be great to add, some of our sites have this while some do not