api(jsonrpc): Add set_draft_vcard(.., msg_id, contacts)

Add a function setting a vCard containing the given contacts to the message draft. This should
simplify sending contacts as vCards for apps.

deltachat-jsonrpc/src/api.rs

@@ -1476,6 +1476,20 @@ impl CommandApi {
         deltachat::contact::make_vcard(&ctx, &contacts).await
     }
 
+    /// Sets vCard containing the given contacts to the message draft.
+    async fn set_draft_vcard(
+        &self,
+        account_id: u32,
+        msg_id: u32,
+        contacts: Vec<u32>,
+    ) -> Result<()> {
+        let ctx = self.get_context(account_id).await?;
+        let contacts: Vec<_> = contacts.iter().map(|&c| ContactId::new(c)).collect();
+        let mut msg = Message::load_from_db(&ctx, MsgId::new(msg_id)).await?;
+        msg.make_vcard(&ctx, &contacts).await?;
+        msg.get_chat_id().set_draft(&ctx, Some(&mut msg)).await
+    }
+
     // ---------------------------------------------
     //                   chat
     // ---------------------------------------------