Nanosecond precision epoch ts on encoder and decoder

[kcrandall]

Because C# has the limitation of 100 nanosecond precision on the DateTime object there is no way to add nanosecond time to fauna. Sometimes a user may want to store a nanosecond precision Time via a Unix epoch timestamp. Fauna has the Epoch function that can accomplish this. The encoder could take a long and run it through that function after detecting a [FaunaEpoch(EpochPrecision.Nanosecond)] attribute. Then the decoder would convert fauna time into a ts long value.

[n400]

Thanks for the suggestion. We have an internal ticket to track this now (DRV-536).