Rewrite serverlist

Current frontend for the server list is quite bad looking and limited feature wise.

Many features could be added to the backend too.

Here is my wish list for a completely rewritten serverlist:

• Better Looking Website
  • Use Icons for flags and ping, just like the ingame server list
  • More readable values (player count, max and average are too hard to distinguish without looking to the header multiple times)
  • Makes links in description clickable, or add more URL fields to announce (not user friendly to select + copy/paste, especially since if the content update it break the current selection)
  • One-click copy of server URL and port (until https://github.com/minetest/minetest/issues/7400 become a thing)
  • Modern looking website overall (should at the very least match the Minetest website color wise, there is a ton of other space for improvements)
  • Adaptive UI for mobile phones
  • Lighthouse report is not really good (except performance wise) for accessibility, SEO and best practices
  • Give the website its own icon just like the ContentDB
  • Separate embed view from regular view
• Features
  • Make website an installable PWA
  • Provide complete OpenAPI specification for the REST API
  • Allow the creation of notification alerts (with webworkers together with the PWA) when a specific server comme back to life or have more than x players.
  • More ways of researching in the server list (currently we can only filter by protocol version); text based, player count based, mod based, etc
  • One-click search for a server mod/game in CDB
• More complex stuff / require Minetest change
  • Allow a server to provide an icon
  • Allow a server to provide screenshots
  • Provide a tags system to classify servers into categories
  • Add player reviews just like CDB packages (require CDB OAuth or merging serverlist and CDB)

I looked a bit into rewriting the frontend part, but sadly I am pretty bad at designing :(

The issue names no files, tests, or entry points, so first map the existing server-list frontend and REST API before choosing a focused item from the wishlist. A useful contribution would need an agreed scope, clear acceptance criteria, and a defined way to verify the selected frontend or backend change.