### Problem description
The bug can be reproduced as follows:
1) Using Ctrl-F do a search for a term that occurs several times in the
file. and press F3 to visit them.
2) Go back to the fop of the file and insert 3 blank lines.
3) Pressing F3 once or many times will not find the term entered above.
### Implementation description
The reason for this bug is that the positions of the matches are not
being reset when changes can potentially move them.
The fix consists on resetting the search locations when changing the
contents of the file and redoing the search after the changes are made.
The bug was specially problematic when doing replace because the
replacement position would be identified as a match. This PR fixes
replace as well.
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Co-authored-by: Nik <werwolv98@gmail.com>
96a588bd86