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/index.js b/app/index.js
index 6673c29..b121d24 100644
--- a/app/index.js
+++ b/app/index.js
@@ -82,6 +82,7 @@
 import remote_console_window_controller from './server-control/controllers/remote-console-window-controller.js';
 import server_led_controller from './server-control/controllers/server-led-controller.js';
 import kvm_controller from './server-control/controllers/kvm-controller.js';
+import vm_controller from './server-control/controllers/virtual-media-controller.js';
 
 import server_health_index from './server-health/index.js';
 import inventory_overview_controller from './server-health/controllers/inventory-overview-controller.js';
@@ -99,7 +100,6 @@
 import network_controller from './configuration/controllers/network-controller.js';
 import snmp_controller from './configuration/controllers/snmp-controller.js';
 import firmware_controller from './configuration/controllers/firmware-controller.js';
-import vm_controller from './configuration/controllers/virtual-media-controller.js';
 
 import users_index from './users/index.js';
 import user_accounts_controller from './users/controllers/user-accounts-controller.js';