[stable31] feat(settings): add admin & user setting iframe

[backportbot]

Backport of #4373

Warning, This backport's changes differ from the original and might be incomplete ⚠️

Todo

• Review and resolve any conflicts

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[elzody]

@codewithvk The CI will fail here and it is related, but for me figuring out the issue is non-trivial and to get main passing I have had to resort to commenting out a line -- but on 31 we shouldn't break any functionality more than it already might be, so for now once the CI is done running we will just have to merge and follow up with fixes there.

If it helps, commenting out this line fixes everything again:

richdocuments/lib/Controller/WopiController.php

Line 182 in c21b8b6

$response['UserSettings'] = $this->generateSettings($userId, 'userconfig');

And on my CI testing on main I get an error like this from the CI logs, not sure if helpful:

{
  "reqId": "uRPn10ieU0BZg8aGaFVs",
  "level": 3,
  "time": "2025-02-25T19:21:17+00:00",
  "remoteAddr": "172.18.0.2",
  "user": false,
  "app": "richdocuments",
  "method": "POST",
  "url": "/index.php/apps/richdocuments/wopi/settings/upload?fileId=%2Fsettings%2Fuserconfig%2Fbrowsersetting%2Fbrowsersetting.json&access_token=jD9tkIfI3Yti1rAdvv91KXqXZuBhWuiy",
  "message": "Failed to validate WOPI access",
  "userAgent": "COOLWSD HTTP Agent 24.04.12.4",
  "version": "32.0.0.0",
  "exception": {
    "Exception": "OCP\\Files\\NotPermittedException",
    "Message": "",
    "Code": 0,
    "Trace": [
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/lib/private/AppFramework/Middleware/MiddlewareDispatcher.php",
        "line": 73,
        "function": "beforeController",
        "class": "OCA\\Richdocuments\\Middleware\\WOPIMiddleware",
        "type": "->"
      },
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 106,
        "function": "beforeController",
        "class": "OC\\AppFramework\\Middleware\\MiddlewareDispatcher",
        "type": "->"
      },
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/lib/private/AppFramework/App.php",
        "line": 161,
        "function": "dispatch",
        "class": "OC\\AppFramework\\Http\\Dispatcher",
        "type": "->"
      },
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/lib/private/Route/Router.php",
        "line": 307,
        "function": "main",
        "class": "OC\\AppFramework\\App",
        "type": "::"
      },
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/lib/base.php",
        "line": 1034,
        "function": "match",
        "class": "OC\\Route\\Router",
        "type": "->"
      },
      {
        "file": "/home/runner/actions-runner/_work/richdocuments/richdocuments/index.php",
        "line": 24,
        "function": "handleRequest",
        "class": "OC",
        "type": "::"
      }
    ],
    "File": "/home/runner/actions-runner/_work/richdocuments/richdocuments/apps/richdocuments/lib/Middleware/WOPIMiddleware.php",
    "Line": 64,
    "message": "Failed to validate WOPI access",
    "exception": {},
    "CustomMessage": "Failed to validate WOPI access"
  }
}

Have not been able to figure out if something is wrong in richdocuments or upstream Collabora, was hoping you can help?