Add support for temporal data types in result set

[andygrove]

We need the ability to retrieve DATE, TIME, TIME_WITH_TIMEZONE, TIMESTAMP, and TIMESTAMP_WITH_TIMEZONE data types from query result sets, as defined by ANSI SQL [1].

We should probably use the chrono crate? [2]

[1] https://crate.io/docs/sql-99/en/latest//chapters/02.html#sql-data-types
[2] https://docs.rs/chrono/0.4.10/chrono/