[modal] form in modal with image doesn’t utilise full width

[jamessampford]

Bug Report

If a form is included in a modal with an image to the side, the form fields do not use all the available space

By changing flex to flex: 1 0 auto on description class, it seems to then use the full width, but not sure if better solution exists or if this breaks something else

Testcase

https://jsfiddle.net/f9uwm0ov/

Version

2.9.4

[ko2in]

I took a quick look and I guess it's OK to allow description container to use the remaining space.
It gives the same result as long as the image container uses variation for it's size.

Even if it doesn't, then the description container is going to use the remaining space after the image container which is the same as current implementation.

I'll submit a PR for this.

[ko2in]

Fixed in #3269