replace deprecated page object in frontend

page object is no longer global, direct old use of window.location.href
is the new method.

Change-Id: Idb47cf9fd5eb776ee0be33949bec816fad45ba35

gr-serviceuser/gr-serviceuser-create.js

diff --git a/gr-serviceuser/gr-serviceuser-create.js b/gr-serviceuser/gr-serviceuser-create.js
index 4ca98d9..fa5144b 100644
--- a/gr-serviceuser/gr-serviceuser-create.js
+++ b/gr-serviceuser/gr-serviceuser-create.js
@@ -71,10 +71,7 @@
   }
 
   _forwardToDetails() {
-    page.show(
-        this.plugin.screenUrl()
-        + '/user/'
-        + this._accountId);
+    window.location.href = `${this.plugin.screenUrl()}/user/${this._accountId}`;
   }
 
   _getConfig() {

gr-serviceuser/gr-serviceuser-list.js

diff --git a/gr-serviceuser/gr-serviceuser-list.js b/gr-serviceuser/gr-serviceuser-list.js
index a8315bc..b579164 100644
--- a/gr-serviceuser/gr-serviceuser-list.js
+++ b/gr-serviceuser/gr-serviceuser-list.js
@@ -126,7 +126,7 @@
   }
 
   _createNewServiceUser() {
-    page.show(this.plugin.screenUrl() + '/create');
+    window.location.href = `${this.plugin.screenUrl()}/create`;
   }
 }