Add lang atttribute on multilingual names, wikidata/wikipedia fields (#10716)

This improves rendering of CJK names that contain unified ideographs that share a unicode codepoint, such as 化.

test/spec/ui/fields/localized.js

@@ -166,4 +166,14 @@ describe('iD.uiFieldLocalized', function() {
             done();
         }, 20);
     });
+
+    it('has a lang attribute on an existing multilingual name field', function(done) {
+      var localized = iD.uiFieldLocalized(field, context);
+      localized.tags({'name:de': 'Value'});
+      window.setTimeout(function() {
+        selection.call(localized);
+        expect(selection.selectAll('.localized-value').attr('lang')).to.eql('de');
+        done();
+      }, 20);
+    });
 });