Generate select list if a property has an enum value

@markie, I have fixed this on the drush generator side.

I will begin the fix for the form.

@markie, this commit has the fix
https://git.drupalcode.org/project/sdc_styleguide/-/commit/c3526c2a1cc43...

So it is available on the dev version.

I pushed the latest dev into Drupalpod and updated the Heading demo component to be an enum. The form rendered properly, but I got an error when clicking submit. Setting to Needs Work to review more later.

My earlier issue was a semantic issue in the component.yml.. Merge request created that gives a sample of this change. After review and RTBC this should be considered completed.