3.x: Adjust for zero token nodes

[Bouncheck]

Adds ZeroTokenNodesIT that checks the behaviour of the driver when zero-token
nodes are involved.

Changes behavior of the driver in regards to zero-token nodes. Those nodes
will be ignored if encountered in system.peers table. If provided as a
contact point, the driver will attempt to connect to it, but will not populate
metadata with it. This results in zero-token nodes being not included in
query planning.

Note that the isValidPeer method had the check for nullity of tokens column
moved from extended peer check to the regular check.

[dkropachev]

@Bouncheck , thanks, looks good, could you please add another test for Zero-token Datacenter from #317

[dkropachev]

@Bouncheck , please consider fixing code not to log following error:

WARN  [cluster1-worker-2] 2024-09-17 16:10:28,825 ReplicationStategy.java:204 - Error while computing token map for keyspace keyspace1 with datacenter eu-northscylla_node_north: could not achieve replication factor 3 (found 0 replicas only), check your keyspace replication settings.

[Bouncheck]

Added some tests. The current version slightly differs from what's proposed in #317 , for example driver won't fail when executing queries after connecting to zero-token DC. It just won't direct queries to it.

[Bouncheck]

@Bouncheck , please consider fixing code not to log following error:

WARN  [cluster1-worker-2] 2024-09-17 16:10:28,825 ReplicationStategy.java:204 - Error while computing token map for keyspace keyspace1 with datacenter eu-northscylla_node_north: could not achieve replication factor 3 (found 0 replicas only), check your keyspace replication settings.

In one of the tests i create a table in a new keyspace with general replication_factor in multi-dc setting and I do not see this error now.

[Bouncheck]

Some of the tests fail, because their hosts have null tokens but are not meant to be treated as zero-token nodes. This needs more or different adjustments.