[aurora] Support monitoring v2 clusters

[Lewenhaupt]

Feature scope

Aurora V2

Describe your suggested feature

monitorAuroraCluster throws an error if the instance is not a ServerlessCluster, which is fine for v1 clusters, but not for v2 clusters as they are instead defined by the the instance types. I believe the check should be a bit more flexible to allow for usage with v2 as they have the same metrics.