Added a fix: dateTime member functions to work with dateTime formatted string for LDEV-3384

[cfmitrah]

https://luceeserver.atlassian.net/browse/LDEV-3384

By this fix

• dateTime member functions works with dateTime formatted strings ( ex:- "10/10/2022", "10 jan 2022" )
• non date formatted strings( ex:- "lucee", "coldfusion" ) throw error like The function [diff] does not exist in the String.
• Lucee has two compare() member functions ( String.compare(), DateTime.compare() ). string and dateTime formatted string invoke String.compare(). DateTime.compare() invokes DateTime.compare().