Timestamp for fct_monthly_modal_time_series_safety_and_service

[evansiroky]

User story / feature request

As a data analyst,
I would like to have a convenience column in a date or datetime format in the fct_monthly_modal_time_series_safety_and_service table,
So that I can make a query to determine the date associated with each record.

Acceptance Criteria

A new column is added that parses the year and month columns to create a date or datetime column that can be used to make a temporal query of each record.

Notes

It appears the existing dt column merely references the date that the NTD raw data was loaded into the pipeline.