Expose accurate seconds on Entity LastModified timestamps

How:

The DateTime object exposed via the LastModified field on Entities in the Remoting API is updated to be accurate down to the second and if possible millisecond of when the latest Entity update occurred, or alternatively a new field with higher accuracy is added if this change would break backward compatibility.

Why:

Currently the DateTime objects exposed on LastModified are only accurate down to the minute, with the seconds always set to 00 irregardless of when the Entity was actually updated. This causes issues in integrations that need to be able to process entity updates out of order, since if two updates on the same Entity are made in the same minute then LastModified will show the same timestamp for both of them, making it impossible to know which update happened first.

For Who:

Inriver systems with integrations that need to process entity updates out of order.

Impact:

There is no simple way to avoid this issue at the moment.

Additional context:

n/a