Sync: Tags not immediately synced from other device when Tags field has focus

### Expected

I expect that when I add a tag to a note, it will be immediately synced between devices.

### Observed

When I add a tag to a note from the iOS app, it is immediately synced to other devices (iOS app on another device and the web app).

However, if I leave the cursor in the tag field in the iOS app, and edit the tags on another device, the remote tag changes are not synced to the iOS app.

### Reproduced

1. Open Simplenote on an iOS device and on another device (e.g. the web app on a laptop).
2. In the iOS app, create a new note with some content.
3. On the other device, confirm the note is synced.
4. In the iOS app, add a tag to the note (and leave the cursor in the Tag field).
5. On the other device, confirm the tag is synced.
8. On the other device, add a tag to the note.
9. In the iOS app, notice that the new tag is **not** synced.
10. In the iOS app, go back to the notes list and then reopen the note. Notice that now remote tag changes are synced immediately.

Make|Model|iOS Version|App Version
-|-|-|-
Apple|iPad Mini|iPadOS 13.4.1|4.18.0.0 TestFlight beta
Apple|iPhoneXS|iOS 13.4.1|4.19.0.0 TestFlight beta

Reproduce the issue using the listed iOS steps, leaving the cursor in the Tags field while adding a tag from another device. Trace the iOS note and tag synchronization behavior during that focused state; done means remote tag changes appear immediately without leaving and reopening the note.

Written by the indexing model from the issue text.