Add support for picklist fields

[jongpie]

Currently, picklist fields are rendered as textboxes - they should instead be properly rendered as a dropdown. Requested by macmouse on SFXD - thanks for the feedback!

[ssk42]

Good morning! It looks like this issue is still open. Would you be open for a contribution for this? @jongpie

[jongpie]

@ssk42 I would love a contribution for this! I had hoped to work on this a while ago, but the issue has been open for over a year 😅 If you're interested in working on this, I'm more than happy to review & merge your changes whenever it's ready.