Fn::ForEach can't ref logical ids of resources created with &{Identifier}

### Resource Name

Fn::ForEach

### Details

The `&{Identifier}` syntax strips non alpha-numeric chars from the iterating identifier, but that syntax only works in the OutputKey and not the OutputValue. This means that you can create resources in the Fn::ForEach that can't be referenced by other resources in the iteration.

I think this could be functionally resolved a few different ways:
* Being able to resolve &{} in the OutputValue
* Making something like Identifier.Index that is just a number that increments per iteration that could be used in the OutputKey
* Allowing more nested structure of the collection being iterated on... maybe a pipe delimited tuple or something? So non.alpha.numeric01|X01,non.alpha.numeric02|X02 could be passed in and then unpacked into a matching number of identifiers specified
* Allowing !Sub to work on the output key and then maybe the one above could be implemented through existing !Split / !Select function calls....

Start with the Fn::ForEach behavior described in the issue, especially how &{Identifier} is handled in OutputKey versus OutputValue. Done means selecting a supported way for resources created in an iteration to be referenced by other resources; the issue names no repository files or tests.

Written by the indexing model from the issue text.