Add File APIs for setting timestamps (creation time, last write time, last access time)

[augustoproiete]

We currently don't expose the APIs in System.IO.File for setting the timestamps in files:

• SetCreationTime
• SetCreationTimeUtc
• SetLastAccessTime
• SetLastAccessTimeUtc
• SetLastWriteTime
• SetLastWriteTimeUtc

[DurveshKumarPal]

hey, @augustoproiete I would like to work on Issue could you Assigned to me.

[augustoproiete]

@DurveshKumarPal Thanks for the offer, but the work for this ticket is already done - just awaiting review & merge.

I assigned #2056 to you though as that one is still open and no work has been done yet