loopback encontre ou crie
await server.models.Role.findOrCreate(
{where: {name: val} },
{name: val}
);
GutoTrosla
await server.models.Role.findOrCreate(
{where: {name: val} },
{name: val}
);
PersistedModel.upsertWithWhere([where], data, callback)
PersistedModel.upsert(data, callback)