I should run this, I've wanted to do a similar search.
Discussion
you can use notedeck to pull down data by visiting your profile page. once you have your data locally you can search it
on macOS you have to do:
ndb -d ~/Library/Application\ Support/notedeck/db
to use the notedeck db
on linux its:
ndb -d ~/.local/share/notedeck/db
you can also do something more manually by using `ndb import` and pulling data from the relay. import is kinda buggy right now though when importing lots of data.