API: provide compat for Timestamp  now/today/utcnow class methods (GH5339)
closes #5339

cc @JanSchulz , cc @cancan01 any other methods you think are missing?
 @jreback it's cancan101 !
 `fromtimestamp`,  `utcfromtimestamp`, `strptime` and `combine` are also broken.
 @cancan101 sorry...typo!
 @cancan101 ...want to add them? should be straightforward...just add tests and push to this PR!
 @cancan101 pls create a new issue for these other methods
