Add upload field

[JessChowdhury]

Feature request from discord to add a new upload option to the form builder fields

[jacobsfletch]

This plugin is now being maintained in the Packages Directory of the Payload Monorepo. This repo will soon be archived and all open issues including this one will be closed. This issue has already been added to this open discussion, though, so that it will not get lost. Please refer to that discussion for more details and to continue the conversation.