feat: Add ConfigSynced event

Add an event for a case if a multi-device synced config value changed. Maybe the app needs to
refresh smth on such an event. For uniformity it is emitted on the source device too. The value is
omitted, otherwise it would be logged which might not be good for privacy.

deltachat-ffi/deltachat.h

@@ -6206,6 +6206,18 @@ void dc_event_unref(dc_event_t* event);
 #define DC_EVENT_SELFAVATAR_CHANGED               2110
 
 
+/**
+ * A multi-device synced config value changed. Maybe the app needs to refresh smth. For uniformity
+ * this is emitted on the source device too. The value isn't reported, otherwise it would be logged
+ * which might not be good for privacy. You can get the new value with
+ * `dc_get_config(context, data2)`.
+ *
+ * @param data1 0
+ * @param data2 (char*) Configuration key.
+ */
+#define DC_EVENT_CONFIG_SYNCED                    2111
+
+
 /**
  * webxdc status update received.
  * To get the received status update, use dc_get_webxdc_status_updates() with

deltachat-ffi/src/lib.rs

@@ -556,6 +556,7 @@ pub unsafe extern "C" fn dc_event_get_id(event: *mut dc_event_t) -> libc::c_int
         EventType::SecurejoinJoinerProgress { .. } => 2061,
         EventType::ConnectivityChanged => 2100,
         EventType::SelfavatarChanged => 2110,
+        EventType::ConfigSynced { .. } => 2111,
         EventType::WebxdcStatusUpdate { .. } => 2120,
         EventType::WebxdcInstanceDeleted { .. } => 2121,
     }
@@ -583,6 +584,7 @@ pub unsafe extern "C" fn dc_event_get_data1_int(event: *mut dc_event_t) -> libc:
         | EventType::Error(_)
         | EventType::ConnectivityChanged
         | EventType::SelfavatarChanged
+        | EventType::ConfigSynced { .. }
         | EventType::IncomingMsgBunch { .. }
         | EventType::ErrorSelfNotInGroup(_) => 0,
         EventType::MsgsChanged { chat_id, .. }
@@ -643,7 +645,8 @@ pub unsafe extern "C" fn dc_event_get_data2_int(event: *mut dc_event_t) -> libc:
         | EventType::ConnectivityChanged
         | EventType::WebxdcInstanceDeleted { .. }
         | EventType::IncomingMsgBunch { .. }
-        | EventType::SelfavatarChanged => 0,
+        | EventType::SelfavatarChanged
+        | EventType::ConfigSynced { .. } => 0,
         EventType::ChatModified(_) => 0,
         EventType::MsgsChanged { msg_id, .. }
         | EventType::ReactionsChanged { msg_id, .. }
@@ -722,6 +725,10 @@ pub unsafe extern "C" fn dc_event_get_data2_str(event: *mut dc_event_t) -> *mut
             .to_c_string()
             .unwrap_or_default()
             .into_raw(),
+        EventType::ConfigSynced { key } => {
+            let data2 = key.to_string().to_c_string().unwrap_or_default();
+            data2.into_raw()
+        }
     }
 }