feat(nautobotop): determine the username from the supplied token

[cardoe]

Avoid an issue where the username supplied is different than the token
the user is for by always looking up the user that the token belongs to
for the queries.

Purposefully did not run:

• make manifests
• make copy-crds-to-helm

So that we have a transition period in removing the username.

[abhimanyu003]

I like the change but looks like it not yet ready to merge.

Few things I noticed that response from Nautobot api is like this, it only exposing displayname and not the username

{
  "count": 1,
  "next": null,
  "previous": null,
  "results": [
    {
      "id": "11a6f69f-89df-47b5-a1a9-cda64bd7d324",
      "object_type": "users.token",
      "display": "yTCXFP (admin)",
      "url": "http://192.168.194.196/api/users/tokens/11a6f69f-89df-47b5-a1a9-cda64bd7d324/",
      "natural_slug": "11a6f69f-89df-47b5-a1a9-cda64bd7d324_11a6",
      "key": "ck7bsgfapcW2UNyzfaNf7qD07SRAcPog38yTCXFP",
      "expires": null,
      "write_enabled": true,
      "description": "",
      "created": "2026-04-02T09:48:23.056821Z"
    }
  ]
}

Other concerns.

• If there are multiple CRs with different tokens, they'll all share the same cached username from whichever CR reconciled first.

• If the token is rotated, the cached username becomes stale. There's no invalidation path since resolvedUsername is set once and never cleared. Untill we restart the Nautobot OP Controller POD.

Sure I want to add this change, but there can some slightly better way.