Add basic NXM collections link parsing

[Silarn]

No description provided.

[Al12rs]

Code is a bit confusing here, I would suggest something like:

QUrl nxm(url);
QUrlQuery query(nxm);

static const QRegularExpression modRegex(
    "nxm://[a-z0-9]+/mods/(\\d+)/files/(\\d+)",
    QRegularExpression::CaseInsensitiveOption);
static const QRegularExpression collectionRegex(
    "nxm://[a-z0-9]+/collections/([a-z0-9]+)/revisions/(\\d+)",
    QRegularExpression::CaseInsensitiveOption);

m_Game = nxm.host();

if (const auto modMatch = modRegex.match(url); modMatch.hasMatch()) {
  m_Collection = false;
  m_ModId      = modMatch.captured(1).toInt();
  m_FileId     = modMatch.captured(2).toInt();
  m_Key        = query.queryItemValue("key");
  m_Expires    = query.queryItemValue("expires").toInt();
  m_UserId     = query.queryItemValue("user_id").toInt();
} else if (const auto collectionMatch = collectionRegex.match(url);
           collectionMatch.hasMatch()) {
  m_Collection         = true;
  m_CollectionId       = collectionMatch.captured(1);
  m_CollectionRevision = collectionMatch.captured(2).toInt();
} else {
  throw MOBase::InvalidNXMLinkException(url);
}