chore: add script for a quick integration test

Summary:
This is just a little script that will run a search and print out the timings
for each of the searches that ivy will preform.

For example running

nvim -l ./scripts/integration.lua /path/to/repo test 2> /dev/null

will output

t       0.074737
te      0.016494
tes     0.018898
test    0.017214

Test Plan:
Does not really require testing, this is a little helper script for
development. If it does not work on another machine then we can cross that
bridge when we come to it.

Reviewers: AdeAttwood

Reviewed By: AdeAttwood

Differential Revision: https://ph.baln.co.uk/D2