Tag list: allow more meaningful sort order / groups

[daganzdaanda]

The tags / meberships window lists all entries sorted alphabetically.
I think it would be enhancing the user experience and efficiency if there was a possibility to have keys grouped by some other criteria.

As an example, look at the keys for phone, fax, mobile, email, website etc. If these are mapped with the "contact:*=*" scheme, they are grouped together. But the more popular way to tag this info is without "contact" prefix, and so the items fall on different places in the list.
Could we get a kind of key-group-preset system? So that a user can define keys that should show up grouped in a certain sequence? This could help with special interest mapping, if you only want to focus on some tags.

Thinking further, it would make sense to by default "rank" keys by their importance.
The sequence of the alphabet does not mean anything for keys. But there are definitely some keys that are in a higher category than others: name=* is a special case, but highway, shop, amenity, landuse, man_made... etc are more important than the addr:* or contact:* keys. If you look at any shop=* POI right now, the main tag can be far down the list.
So I would like to see the main tags on top of the tag list, ideally followed by a meaningful sequence of the other tags. Contact and address tags should be grouped, and users should be able to define their own presets if they want a different sort / group order. In a way this would come closer to what ID is doing with their input mask, but not as restrictive. (As far as I remember, ID will only show one "main" object type. To work with a combined tourism=hotel / amenity=restaurant you need the tag list. JOSM could show both the tourism and amenity on top of the list.)