(Value)Option.zip(3)

# (Value)Option.zip(3)

I propose we add `Option.zip`, `Option.zip3`, `ValueOption.zip`, and `ValueOption.zip3` that act just like `Seq.zip` and `Seq.zip3`.

The existing way of approaching this problem in F# is to write a long `map` yourself.
```fs
module Option =
let zip x y = Option.map2 (fun x y -> x, y) x y
let zip3 x y z = Option.map3 (fun x y z -> x, y, z) x y z
module ValueOption =
let zip x y = ValueOption.map2 (fun x y -> struct(x, y)) x y
let zip3 x y z = ValueOption.map3 (fun x y z -> struct(x, y, z)) x y z
```

## Pros and Cons

The advantages of making this adjustment to F# are
1. Consistency with `zip` and `zip3` of `List`, `Array` and `Seq`
2. Convenience
3. Conciseness

The disadvantage of making this adjustment to F# is the difficulty of choosing between reference tuples and struct tuples as the return type for the `zip` and `zip3` on `ValueOption`.

## Extra information

Estimated cost (XS, S, M, L, XL, XXL): XS

Related suggestions: None

## Affidavit (please submit!)

Please tick this by placing a cross in the box:
* [x] This is not a question (e.g. like one you might ask on [stackoverflow](http://stackoverflow.com)) and I have searched stackoverflow for discussions of this issue
* [x] I have [searched both open and closed suggestions on this site](http://github.com/fsharp/fslang-suggestions/issues) and believe this is not a duplicate
* [x] This is not something which has obviously "already been decided" in previous versions of F#. If you're questioning a fundamental design decision that has obviously already been taken (e.g. "Make F# untyped") then please don't submit it.

Please tick all that apply:
* [x] This is not a breaking change to the F# language design
* [x] I or my company would be willing to help implement and/or test this

## For Readers

If you would like to see this issue implemented, please click the :+1: emoji on this issue. These counts are used to generally order the suggestions by engagement.

Start by comparing the requested Option.zip, Option.zip3, ValueOption.zip, and ValueOption.zip3 APIs with Seq.zip and Seq.zip3 and the existing map2/map3 examples. Done requires resolving whether ValueOption should return reference or struct tuples, then agreeing on and implementing the four APIs.

Written by the indexing model from the issue text.