Simplify
Rename TagEditor -> EntityEditor

It's going to be used to edit relation memberships as well
as tags.
Rename Taglist -> RawTagEditor
Extract iD.ui.Disclosure
Display relation memberships in inspector

* Preset icon of relation
* Preset name of relation
* Name of relation
* Member role
* Delete button

All currently unstyled.
Extract iD.util.localeName
Add common relation presets

Multipolygon is not included because multipolygon relations
should be matched by other presets.