ESQL Date Nanos Addition and Subtraction (elastic#116839)

Resolves elastic#109995

This adds support and tests for addition and subtraction of date nanos with periods and durations. It does not include support for date_diff, which is a separate ticket (elastic#109999). The bulk of the PR is testing, the actual date math is all handled by library functions.

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Co-authored-by: Elastic Machine <[email protected]>

Author: not-napoleon

docs/reference/esql/functions/kibana/definition/add.json

@@ -415,6 +415,14 @@ public static boolean isDateTimeOrTemporal(DataType t) {
         return isDateTime(t) || isTemporalAmount(t);
     }
 
+    public static boolean isDateTimeOrNanosOrTemporal(DataType t) {
+        return isDateTime(t) || isTemporalAmount(t) || t == DATE_NANOS;
+    }
+
+    public static boolean isMillisOrNanos(DataType t) {
+        return t == DATETIME || t == DATE_NANOS;
+    }
+
     public static boolean areCompatible(DataType left, DataType right) {
         if (left == right) {
             return true;