4.x: Implement PartitionerMap

[dkropachev]

Since in scylla CDC tables should get cdc partitioner instead default one, we need something that would hold that partitioner information and provide it upon request.
Currently it is done in inderect way at

java-driver/core/src/main/java/com/datastax/oss/driver/internal/core/cql/Conversions.java

Line 390 in cf9f8f0

Partitioner partitioner = PartitionerFactory.partitioner(variableDefinitions, context);

Which creates unnecessary confusion, to get rid of which we need an instance with following API available at metadata level:

public interface PartitionerMap {
  public Partitioner DefaultPartitioner();
  
  public Partitioner GetTablePartitioner(CqlIdentifier ks, CqlIdentifier table);
}

When it is done we need to get rid of prepared statement partitioner hack.