feat(CIE): Implement OIDC RP Service with login, callback, and session management

common/OidcUserClaims.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <json/json.h>
+
+#include <optional>
+#include <string>
+
+namespace visione::oidc
+{
+struct NormalizedUserClaims
+{
+    std::string issuer;
+    std::string subject;
+    std::string firstName;
+    std::string lastName;
+    std::string email;
+    std::string fiscalCode;
+    Json::Value rawClaims;
+};
+
+std::optional<NormalizedUserClaims> normalizeIdTokenClaims(
+    const std::string &issuer,
+    const Json::Value &claims);
+
+std::optional<NormalizedUserClaims> mergeUserClaims(
+    const std::string &issuer,
+    const Json::Value &idTokenClaims,
+    const Json::Value &userinfoClaims);
+}  // namespace visione::oidc