Dropdown component should adjust its callout width according to the longest option

Hi all,

basically just copied the text from this request https://github.com/microsoft/fluentui/issues/16181
I would basically propose that the dropdown dropdown menu behaves like the combobox dropdown menu.
Or (non-breaking) that there is an option to make it so :)

Cheers
Hannes

Start by locating the dropdown component and the combobox dropdown behavior referenced in the issue. Confirm how callout width is currently determined, then verify that the dropdown can size to its longest option or expose a non-breaking option, with behavior matching the request linked in the issue.

Written by the indexing model from the issue text.