feat: Add EventType::CallMissed and emit it for missed calls (#7840)

Before, only `CallEnded` was emitted for missed calls, or, if a call arrives already being stale,
`IncomingMsg`. Now:
- `CallMissed` is emitted in addition to `CallEnded`.
- `IncomingMsg` is replaced with `CallMissed` for stale calls.
Having only one event type for missed calls should simplify handling them in the apps.

This doesn't emit `CallMissed` for those who aren't allowed to call us. Also, don't emit `CallEnded`
if the caller isn't allowed to call us and the call wasn't accepted, as there's no previous
`IncomingCall` event in this case.

deltachat-jsonrpc/src/api/types/events.rs

@@ -463,6 +463,14 @@ pub enum EventType {
         chat_id: u32,
     },
 
+    /// Call missed.
+    CallMissed {
+        /// ID of the info message referring to the call.
+        msg_id: u32,
+        /// ID of the chat which the message belongs to.
+        chat_id: u32,
+    },
+
     /// One or more transports has changed.
     ///
     /// UI should update the list.
@@ -658,6 +666,10 @@ impl From<CoreEventType> for EventType {
                 msg_id: msg_id.to_u32(),
                 chat_id: chat_id.to_u32(),
             },
+            CoreEventType::CallMissed { msg_id, chat_id } => CallMissed {
+                msg_id: msg_id.to_u32(),
+                chat_id: chat_id.to_u32(),
+            },
             CoreEventType::TransportsModified => TransportsModified,
 
             #[allow(unreachable_patterns)]