Add "Admin" tab to the registrar console

This tab will set the "allowedTlds", but might have other functionality in the
future.

It is based on (branches from) the security-settings tab, because I'm copying the functionality of the "whitelisted IPs" to the "allowed TLDs": they are both lists of "arbitrary" strings that you can remove from and add to.

There are a lot of moving parts in this CL, because of how all the different elements need to interact, and how intertwined they are (for example, we need to disable the admin-settings view for non admins both in the soy and in the JS code)

It's really time to refactor the console given all we've learned... :/

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=220373443

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

@@ -28,6 +28,7 @@ goog.require('registry.registrar.Console');
  *
  * @param {string} xsrfToken populated by server-side soy template.
  * @param {string} clientId The registrar clientId.
+ * @param {boolean} isAdmin
  * @param {string} productName the product name displayed by the UI.
  * @param {string} integrationEmail
  * @param {string} supportEmail
@@ -36,13 +37,14 @@ goog.require('registry.registrar.Console');
  * @param {string} technicalDocsUrl
  * @export
  */
-registry.registrar.main = function(xsrfToken, clientId, productName,
+registry.registrar.main = function(xsrfToken, clientId, isAdmin, productName,
                                    integrationEmail, supportEmail,
                                    announcementsEmail, supportPhoneNumber,
                                    technicalDocsUrl) {
   new registry.registrar.Console({
     xsrfToken: xsrfToken,
     clientId: clientId,
+    isAdmin: isAdmin,
     productName: productName,
     integrationEmail: integrationEmail,
     supportEmail: supportEmail,