Timezone support on Blueprint

Still pending the code on ESPHome to store for when WiFi is out
Pending API doc.
I haven't merged this in another service for now to not break the API, but this should be done for v4.4.0

Solves #2024

components/nspanel_ha_blueprint/subscriptions.h

@@ -0,0 +1,20 @@
+// subscriptions.h
+#pragma once
+
+#include <vector>
+#include <string>
+#include <optional>
+
+namespace nspanel_ha_blueprint {
+
+    struct Subscription {
+        std::string component_id;
+        std::string entity_id;
+        int subscription_id;
+    };
+
+    std::vector<Subscription> subscriptions;
+    std::string subs_component_id;
+    std::string subs_entity_id;
+
+}  // namespace nspanel_ha_blueprint