[UX] Default drop-button action for node types should be 'manage fields'

The default action in a drop button (the one that appears first, as the "button") should always be the action that users want to do most of the time. Secondary actions should fall inside the "drop" and will require an additional click.

For the node type listing, the action that's in the button right now is "Edit" but most users will want the "Manage Fields" option here far more often than "Edit".