multidimensional arrays with ValidIO lead to incorrect inference of the direction

### Discussed in https://github.com/chipsalliance/chisel3/discussions/2038
Reproducible via: https://scastie.scala-lang.org/endbwvnsRBG76vRLUTE8rQ

Start with the linked Scastie reproduction to observe how multidimensional arrays and ValidIO produce the incorrect direction inference. Read discussion 2038 to determine the intended direction and scope; done means the reproduction infers the intended direction and the behavior is covered by a regression test.

Written by the indexing model from the issue text.