Verifies versions in cluster depending on cluster state. When cluster is STABLE check that a node with
a new version relative to the rest of the cluster does not start up and run upgrade tasks
that would mess up the other nodes. To allow for nodes that have been killed and their active status not having timed out yet, before
complete refusal to start up the launcher will wait for up to 5 minutes to allow any active nodes' heartbeats to time
When cluster is in MIXMODE checks if version that node which wants to join the cluster is in version:
- base version of cluster (version before upgrade)
- new version (needs to be newer than version of cluster)
Only two versions are allowed im MIXMODE.