Allow stacked product images to be equal width

[KaichenWang]

Describe the enhancement you'd like

A setting to allow product images to stack and be equal width to each other

Example (was achievable in Dawn v1.0.0)

Describe alternatives you've considered

Stacked product image setting currently defaults to 50% width for images other than the first.

Example in Dawn v9.0.0

Additional context/screenshots

[kimberlyoleiro]

Thanks Kai! This came up recently internally as well. There was a deliberate change that happened in a previous PR. We could look to reverting but it's not high on the priority list at the moment. I'll mark it as such and we can revisit again in the future #1444