Hide the edit/add buttons for fields the user can't update

Currently the /registrar-settings backend endpoint will fail to update any
OWNER fields that a non-OWNER tries to change.

However, the front-end (soy, js) still allow non-OWNERs to try and change
these fields (there's the "edit" or "add" button, and it only fails when you try to "save")

This CL changes the front-end to remove the ability for non-OWNERs to even try
and change these fields. However, it will still let them *view* these fields as
it has interesting and important information.

-------------------------------

In addition - it changes the webdriver tests to include the "edit buttons". Those were never tested before, and now we will test to see if they are indeed displayed or not.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=223845883

java/google/registry/ui/js/registrar/xml_resource_component.js

@@ -37,7 +37,7 @@ goog.forwardDeclare('registry.registrar.Console');
 registry.registrar.XmlResourceComponent = function(
     itemTmpl, eppTmpls, console) {
   registry.registrar.XmlResourceComponent.base(
-      this, 'constructor', console, itemTmpl);
+      this, 'constructor', console, itemTmpl, console.params.isOwner);
 
   /** @type {!Object} */
   this.eppTmpls = eppTmpls;