Move Virtual Media files and route

"Virtual media" was already part of the "Server control" submenu but
the files were at app/configuration and the route was /configuration.

Marta Mazur did a similar file and route move here as part of
supporting multiple Virtual Media endpoints:
https://gerrit.openbmc-project.xyz/c/openbmc/phosphor-webui/+/25218

Tested: Built and loaded on a Witherspoon. The VM route is now:
        #/server-control/virtual-media. Was able to use the VM
        panel.
Change-Id: Iec46a8ece7ddfbc356bc1e71875def70c4418027
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/app/common/directives/app-navigation.html b/app/common/directives/app-navigation.html
index 329381c..82a4a70 100644
--- a/app/common/directives/app-navigation.html
+++ b/app/common/directives/app-navigation.html
@@ -66,8 +66,8 @@
           <a href="#/server-control/kvm" ng-click="closeSubnav()"
             tabindex="{{(showSubMenu && firstLevel == 'server-control') ? 0 : -1}}">KVM</a>
         </li>
-        <li ng-class="{'active': (path == '/configuration' || path == '/configuration/virtual-media')}">
-          <a href="#/configuration/virtual-media" ng-click="closeSubnav()"
+        <li ng-class="{'active': (path == '/server-control/virtual-media')}">
+          <a href="#/server-control/virtual-media" ng-click="closeSubnav()"
             tabindex="{{(showSubMenu && firstLevel == 'server-control') ? 0 : -1}}">Virtual Media</a>
         </li>
       </ul>