[tlv] add new tlvs for network diagnostic

libotcommissioner.jar, a versatile Java library, provides support for
wide range of TMF message transactions, including MeshCop protocols and
diagnostic TLVs. This PR focuses on integrating all the diagnostic TLVs,
as defined in the spec `10.11.3` into the library's TLV module

src/library/tlv.cpp

@@ -226,9 +226,15 @@ bool Tlv::IsValid() const
         {
         // Network disgnostic layer TLVs
         case Type::kNetworkDiagExtMacAddress:
+<<<<<<< HEAD
             return length == 8;
         case Type::kNetworkDiagMacAddress:
             return length == 2;
+=======
+            return length >= 8;
+        case Type::kNetworkDiagMacAddress:
+            return length >= 2;
+>>>>>>> 20da654 ([tlv] add new tlvs for network diagnostic)
         case Type::kNetworkDiagMode:
             return length == 1;
         case Type::kNetworkDiagTimeout: