Add token to tombstone warning and error log message

If Cassandra scans too many tombstones while reading a partition, then it prints log messages with query based on warning/failure thresholds. The token is not printed in the log message. If tombstones are hurting the instance/replica set, then running force compaction for the partition ("nodetool compact" using start and end tokens i.e. token -/+ some delta) is one of the actions taken to recover. In order to find out the token, someone has to manually connect to cluster and run SELECT TOKEN query. Printing token with the log message helps to avoid manual effort and execute force compaction quickly.