errors.New

[ArquintL]

This PR extends the errors package to (finally!) provide the New function.

[ArquintL]

@jcp19 Was there a particular reason to add wrap.go but not errors.go? It seems strange to me that we provide (some advanced) parts of the errors package but not the most basic one

[jcp19]

@jcp19 Was there a particular reason to add wrap.go but not errors.go? It seems strange to me that we provide (some advanced) parts of the errors package but not the most basic one

the reason is that I never needed errors.go 😄

[jcp19]

LGTM