Debt: don't expose handles in API

[rzhao271]

Actually looking at the handle usages expose to JS, ex: innerPidHandle, handle etc they are only used for internal implementation. I would suggest to remove them from being exposed to JS and operate on pid values instead, on the native side extract the handle when needed using OpenProcess.

Originally posted by @deepak1556 in #584 (comment)

[Tyriar]

Actually let's fix in that PR, see #584 (comment)