Tag picker for attachments

[filipstefansson]

When adding a taxonomy for attachments you only get a basic input field in the modal views, like in a post or when using the grid view on the attachment page:

Someone in the forums [pointed out](​https://wordpress.org/support/topic/tags-picker-for-attachments?replies=3) that this is because the modal view is only for editing the image, and not the attachment post it belongs to. This makes sense when editing a post, but not in the grid view on the attachments page.

The only way to edit tags and categories in the normal way is to press "Edit more details", where you get the proper tags/category pickers. I feel like we should either remove or improve the basic input field. It doesn't really make sense to have a stripped down version in the modal. It's confusing and not very good UX.

[desrosj]

Related #22938.

[joemcgill]

Related: #22938 and #31696.

Would be great if we could use something like Select2 here, but there maybe other improvements possible in the mean time.

[melchoyce]

How are you getting the taxonomy fields to appear?

[karmatosed]

For now removing ui/ux-feedback as we would need steps to show how to get this in order to recommend.