handleErrorWith for Either

[pakoito]

Add it to Either.kt as a member function. It's currently defined inline in the instance so it's a case of copypasting it :D

https://github.com/arrow-kt/arrow/blob/master/modules/core/arrow-core-extensions/src/main/kotlin/arrow/core/extensions/either.kt#L92-L98

[kioba]

I am happy to take it, I will set up the project and finish on the weekend

[pakoito]

Thanks @kioba for the fixxxx

[kioba]

Thank you for letting me contribute! :)