Transact durations should always be millisecond

[qianl15]

For now, workflow context sleep takes in duratioinSec. But JS/TS developers always expect millisecond sleep/timeout. We should match the common practice in V2.

We should also consider adding support for strings like "2 days", "30s" by using the ms package.

[devhawk]

@qianl15 we could add ms package support to the existing sleep function without a breaking change. sleep and sleepms both take a number parameter. If we changed that to number | string we could use the ms if the user passes in a string. Should we separate the non breaking functionality out into a separate issue?

[qianl15]

Yeah that's a good idea. We can separately file an issue (non-breaking) saying we want sleep to support strings.