Implements PowerSubsystem schema

This commit implements the Redfish PowerSubsystem schema and collects
default property values.
PowerSupplies will be implemented in the next commit.

ref:
https://www.dmtf.org/sites/default/files/standards/documents/
DSP0268_2022.2.pdf (6.86 PowerSubsystem 1.1.0)
https://redfish.dmtf.org/schemas/v1/PowerSupply.v1_1_0.json

Tested: Validator and UT passes
1. curl -k  -H "X-Auth-Token: $token" -X GET
https://${bmc}/redfish/v1/Chassis/chassis/PowerSubsystem
{
"@odata.id": "/redfish/v1/Chassis/chassis/PowerSubsystem",
"@odata.type": "#PowerSubsystem.v1_1_0.PowerSubsystem",
"Id": "PowerSubsystem",
"Name": "Power Subsystem",
"Status": {
"Health": "OK",
"State": "Enabled"
}
}

2. bad chassisID
curl -k -H "X-Auth-Token: $token" -X GET https://${bmc}
/redfish/v1/Chassis/badchassisID/PowerSubsystem/
PowerSupplies/powersupply0
{
  "error": {
    "@Message.ExtendedInfo": [
      {
        "@odata.type": "#Message.v1_1_1.Message",
        "Message": "The requested resource of type Chassis named
                   badchassisID was not found.",
        "MessageArgs": [
          "Chassis",
          "badchassisID"
        ],
        "MessageId": "Base.1.13.1.ResourceNotFound",
        "MessageSeverity": "Critical",
        "Resolution": "Provide a valid resource identifier
                      and resubmit the request."
      }
    ],
    "code": "Base.1.13.1.ResourceNotFound",
    "message": "The requested resource of type Chassis named
               badchassisID was not found."
  }
}

Signed-off-by: Chicago Duan <duanzhijia01@inspur.com>
Change-Id: I6885b1777082538eceaf7ea85a8f69966459ee43
diff --git a/redfish-core/lib/power_subsystem.hpp b/redfish-core/lib/power_subsystem.hpp
new file mode 100644
index 0000000..c3b898c
--- /dev/null
+++ b/redfish-core/lib/power_subsystem.hpp
@@ -0,0 +1,64 @@
+#pragma once
+
+#include "app.hpp"
+#include "query.hpp"
+#include "registries/privilege_registry.hpp"
+#include "utils/chassis_utils.hpp"
+
+#include <memory>
+#include <optional>
+#include <string>
+
+namespace redfish
+{
+
+inline void doPowerSubsystemCollection(
+    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
+    const std::string& chassisId,
+    const std::optional<std::string>& validChassisPath)
+{
+    if (!validChassisPath)
+    {
+        BMCWEB_LOG_ERROR << "Not a valid chassis ID" << chassisId;
+        messages::resourceNotFound(asyncResp->res, "Chassis", chassisId);
+        return;
+    }
+
+    asyncResp->res.jsonValue["@odata.type"] =
+        "#PowerSubsystem.v1_1_0.PowerSubsystem";
+    asyncResp->res.jsonValue["Name"] = "Power Subsystem";
+    asyncResp->res.jsonValue["Id"] = "PowerSubsystem";
+    asyncResp->res.jsonValue["@odata.id"] = crow::utility::urlFromPieces(
+        "redfish", "v1", "Chassis", chassisId, "PowerSubsystem");
+    asyncResp->res.jsonValue["Status"]["State"] = "Enabled";
+    asyncResp->res.jsonValue["Status"]["Health"] = "OK";
+
+    asyncResp->res.addHeader(
+        boost::beast::http::field::link,
+        "</redfish/v1/JsonSchemas/PowerSubsystem/PowerSubsystem.json>; rel=describedby");
+}
+
+inline void handlePowerSubsystemCollectionGet(
+    App& app, const crow::Request& req,
+    const std::shared_ptr<bmcweb::AsyncResp>& asyncResp,
+    const std::string& chassisId)
+{
+    if (!redfish::setUpRedfishRoute(app, req, asyncResp))
+    {
+        return;
+    }
+
+    redfish::chassis_utils::getValidChassisPath(
+        asyncResp, chassisId,
+        std::bind_front(doPowerSubsystemCollection, asyncResp, chassisId));
+}
+
+inline void requestRoutesPowerSubsystem(App& app)
+{
+    BMCWEB_ROUTE(app, "/redfish/v1/Chassis/<str>/PowerSubsystem/")
+        .privileges(redfish::privileges::getPowerSubsystem)
+        .methods(boost::beast::http::verb::get)(
+            std::bind_front(handlePowerSubsystemCollectionGet, std::ref(app)));
+}
+
+} // namespace redfish