cql3: add handling paging state for local indexes
cql3: add handling paging state for local indexes

When computing paging state for local indexes, the partition
and clustering keys are different than with global ones:
 - partition key is the same as base's
 - clustering key starts with the indexed column

scylladb/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla