Switch to ISOChronology or make it configurable

Phoenix has historically used the default java.util.GregorianCalendar , and its Joda implementation, org.joda.time.chrono.GJChronology.

However, both the SQL standard, and the modern java.time library uses ISOChronology.

Either switch to ISOChronology, or preferably add an option to switch between GregorianCalendar and ISOChronology.

AFAIU this would have to be a system-wide config.

This is closely related to switching to the java.time API internally.