Add composing notification

Change-Id: I2c052c4395a56ba6acf882cea3be4b82e2fde761
diff --git a/server/src/jamid/jami-signal-interfaces.ts b/server/src/jamid/jami-signal-interfaces.ts
index 851239b..188dfaf 100644
--- a/server/src/jamid/jami-signal-interfaces.ts
+++ b/server/src/jamid/jami-signal-interfaces.ts
@@ -133,3 +133,10 @@
   conversationId: string;
   message: Message;
 }
+
+export interface ComposingStatusChanged {
+  accountId: string;
+  conversationId: string;
+  from: string;
+  status: number;
+}