WvW reconstruction/alliances info under account

[Arky.3072]

Heya,

I would love if at the very least the alliance server name would be exposed during the betas on `/v2/account`.

Example:
```
{
    // ...
    "server": "2003",
    "alliance_server": "5003"
}
```
And then expose those server ID -> name on `/v2/worlds` only during beta events