Use callbacks for transactions config

Suggested Release Note

Transaction settings are now configurable using the same callback pattern used by other environment settings. Here's an example of the new syntax:

Cluster cluster = Cluster.connect(

connectionString,

ClusterOptions.clusterOptions(username, password)

.environment(env -> env

.transactionsConfig(txn -> txn

.durabilityLevel(DurabilityLevel.MAJORITY_AND_PERSIST_TO_ACTIVE)

.metadataCollection(someKeyspace)

.queryConfig(query -> query.scanConsistency(QueryScanConsistency.REQUEST_PLUS))

.cleanupConfig(cleanup -> cleanup

.cleanupWindow(Duration.ofSeconds(10))

.addCollection(someOtherKeyspace))

)

)

);