[lib] Add log and continue in getPushUserInfo when thread missing fro…

…m ThreadStore

Summary:
This has come up twice now: [ENG-9454](https://linear.app/comm/issue/ENG-9454/cannot-read-properties-of-undefined-when-leaving-thread) and [ENG-9946](https://linear.app/comm/issue/ENG-9946/cannot-read-properties-of-undefined-reading-members).

I think it will help us in the future to have a more specific error message. It also is probably a good idea to `continue;` here, in case there are other notifs that we can send successfully.

Test Plan: Ran the code and confirmed the log was printed

Reviewers: angelika, kamil, tomek

Reviewed By: kamil

Differential Revision: https://phab.comm.dev/D14160

lib/push/send-utils.js

@@ -166,6 +166,10 @@ async function getPushUserInfo(
 
   for (const threadID of threadsToMessageIndices.keys()) {
     const threadInfo = thickRawThreadInfos[threadID];
+    if (!threadInfo) {
+      console.log(`getPushUserInfo could not find ${threadID} in ThreadStore`);
+      continue;
+    }
     for (const memberInfo of threadInfo.members) {
       if (
         !isMemberActive(memberInfo) ||