Note Search Inconsistency

### Expected
Search results are consistent.

### Observed
Search results are not consistent.

### Reproduced

How to produce the problem:

1. Open Simplenote with a number of Notes
2. Search for a word/name that appears in a few notes using the "Search Notes" bar, for example type "matching"
3. Edit a note that only contains the matching word once
4. Change that word so the note no longer matches, highlighting and typing over is the most annoying, replace with "replacement"

What will happen is:
!. As you type the "r" for replacement the note with no longer match the search.
2. The note you are just editing gets removed from the search results and the next one that matches is replaced in the edit panel
3. The remaining characters "eplacement" (or until you notice something odd is happening) will end up in the note you had no intention of editng
4. No Ctrl-Z or undo will help will fix the first note that is no longer easily accessible

Make|Model|macOS Version|App Version

Mac (Big Sur 11.6.4) Simplenote Version 2.17

Start by reproducing the problem through the "Search Notes" bar and the edit panel using the listed macOS and Simplenote versions. Trace what happens when the edited note stops matching after the first replacement character. Done means the edited note remains active and subsequent typing cannot be inserted into another search result, with the reported data-loss behavior no longer occurring.

Written by the indexing model from the issue text.