Add VirtualMedia schema to Redfish

This change adds VirtualMedia scheme to Redfish.
Implementation is based on input from virtual-media module
and nbd proxy which is a bmcweb part. The code is used
only in case ndb-proxy is supported in bmcweb
(BMCWEB_ENABLE_VM_NBDPROXY compilation flag).

Tested:
* Manual tests together with nbd proxy and virtual media app
  - For requests: Postman and/or HTTPie, started with logs
    enabled and Valgrind
  - Manual result validation
* Tests ran:
  - GET on collection with manual validation
  - PUT/POST/DELETE on collection
  - GET on item/nonexistent item
  - PUT/POST/DELETE on item
* Redfish Service Validator tested, no new issues found.

Signed-off-by: Przemyslaw Czarnowski <przemyslaw.hawrylewicz.czarnowski@intel.com>
Change-Id: I5415dc0ffe52069fd35bc614b0378bbc4ad41ff6
diff --git a/redfish-core/lib/managers.hpp b/redfish-core/lib/managers.hpp
index 1dab258..dca5933 100644
--- a/redfish-core/lib/managers.hpp
+++ b/redfish-core/lib/managers.hpp
@@ -1560,6 +1560,12 @@
 
         res.jsonValue["EthernetInterfaces"] = {
             {"@odata.id", "/redfish/v1/Managers/bmc/EthernetInterfaces"}};
+
+#ifdef BMCWEB_ENABLE_VM_NBDPROXY
+        res.jsonValue["VirtualMedia"] = {
+            {"@odata.id", "/redfish/v1/Managers/bmc/VirtualMedia"}};
+#endif // BMCWEB_ENABLE_VM_NBDPROXY
+
         // default oem data
         nlohmann::json& oem = res.jsonValue["Oem"];
         nlohmann::json& oemOpenbmc = oem["OpenBmc"];