clean_REDCap debug issues

[pgstevenson]

Catch-all for REDCap cleaning bugs

[pgstevenson]

[x] NA's in time fields will return a warning.

This is normal behaviour and might be useful for large datasets. Resolution is to add quiet = TRUE to the map functions that call {lubridate}. I'm thinking to add clean_REDCap(..., quiet = FALSE), and then add the argument quiet = quiet to all {lubridate} cleaning functions. Setting quiet = TRUE should be done with caution, as this will not return warnings for improperly formatted date strings.

[pgstevenson]

[x] Split date_ into date_ymd, date_mdy, and date_dmy.