Fix Snowflake destination normalization to accept any date-time format.

[sherifnada]

implementation hints

You can probably do this without being completely blocked on the acceptance test piece above.

1. Find the diff between json-schema's date and date-time formats and those accepted by Snowflake for the TIMESTAMP type
2. Write a snowflake-SQL compliant CASE statement which converts ISO8601 date-time formats not supported by Snowflake into a format that is supported (usually you'll need to add : or something similar, the value of the date fundamentally should not change, it should only be a format change). If it helps, use the snowflake login in lastpass to iterate on this statement in the snowflake UI until you get this statement right.
3. Add a DBT macro to use the CASE statement you created above (ask Chris for help if needed)
4. Add any needed normalization integration tests (ask chris for guidance on which tests are needed)