Support Iceberg timestamp types with nanosecond precision: timestamp_ns, timestamptz_ns

[findepi]

in apache/iceberg#8683 Iceberg spec gained two new types which would benefit Trino users significantly, as they add nanos timestamp precision to Iceberg.
apache/iceberg#9008 adds necessary APIs to interact with these types, but likely more Iceberg changes are needed (apache/iceberg#8657) to fully support tables with these types.

[jacobmarble]

@findepi FYI apache/iceberg#8657 is complete.

[findepi]

cc @findinpath @alexjo2144 @cwsteinbach

[ebyhr]

@findepi Are you still going to work on this?

[findepi]

@ebyhr go for it