libpldmresponder:Support GetNumericEffecterValue responder

The GetNumericEffecterValue command is used to return the present
numeric setting of a PLDM Numeric Effecter.
This commit adds responder support for GetNumericEffecterValue Cmd
as mentioned in Section22.3 of DSP0248_1.2.0.
Currently "effecterOperationalState" field in the response msg is
set to "enabled-noUpdatePending". Actual value can be fetched once
the support for EffecterEvent/SetNumericEffecterEnable is added.

Test:
    Using pldmtool raw command
    Success Case:
        pldmtool raw -d 0x80 0x02 0x32 0x23 00
        pldmtool: Tx: 08 01 80 02 32 23 00
        pldmtool: Rx: 08 01 00 02 32 00 00 01 03 03
   Failure Case:
        pldmtool raw -d 0x80 0x02 0x32 0x25 0x00
        pldmtool: Tx: 08 01 80 02 32 25 00
        pldmtool: Rx: 08 01 00 02 32 80

Change-Id: I64a7205d8f69e3925b75b02558a0857b63c70ebf
Signed-off-by: Archana Kakani <archana.kakani@ibm.com>
diff --git a/libpldmresponder/platform.hpp b/libpldmresponder/platform.hpp
index 8d2c74e..8df9625 100644
--- a/libpldmresponder/platform.hpp
+++ b/libpldmresponder/platform.hpp
@@ -77,6 +77,10 @@
                          [this](const pldm_msg* request, size_t payloadLength) {
             return this->setNumericEffecterValue(request, payloadLength);
         });
+        handlers.emplace(PLDM_GET_NUMERIC_EFFECTER_VALUE,
+                         [this](const pldm_msg* request, size_t payloadLength) {
+            return this->getNumericEffecterValue(request, payloadLength);
+        });
         handlers.emplace(PLDM_SET_STATE_EFFECTER_STATES,
                          [this](const pldm_msg* request, size_t payloadLength) {
             return this->setStateEffecterStates(request, payloadLength);
@@ -212,6 +216,15 @@
     Response setNumericEffecterValue(const pldm_msg* request,
                                      size_t payloadLength);
 
+    /** @brief Handler for getNumericEffecterValue
+     *
+     *  @param[in] request - Request message
+     *  @param[in] payloadLength - Request payload length
+     *  @return Response - PLDM Response message
+     */
+    Response getNumericEffecterValue(const pldm_msg* request,
+                                     size_t payloadLength);
+
     /** @brief Handler for getStateSensorReadings
      *
      *  @param[in] request - Request message