Analytics Doesn't Support Fractional Milliseconds For ISO8601 Strings

On 6.0 beta, if you supply an ISO8601 string that has fractionals of a millisecond to a temporal analytics function, the result is always null. This is different from the N1QL query behavior, which accepts the fractions of a millisecond.

This is problematic for stored date/times that have these fractions. For example, in C# DateTime.Now when rendering as ISO8601 using ToString("O") will almost always have fractions of a millisecond. So storing something like a created timestamp on a document will then be mostly unusable in analytics.

Example query:
SELECT VALUE STR_TO_MILLIS("2018-09-29T10:29:18.123123-04:00")
Returns:
null

The same query in N1QL returns (simply stripping the fractions of a millisecond):
1538231358123

This has been observed to affect DATE_DIFF_STR and DATE_ADD_STR as well.