Backend tests for project endpoints

[Sujanadh]

Fixes #169

This pull request contains the updated test data within a compressed zip file. It encompasses all the modifications made in my previous pull request, which was PR #870 in the forked repository. We can close the old pull request.

[spwoodcock]

Thanks @Sujanadh! I will review this tomorrow 👍

Quick note: I think the test_data dir should go under tests not app in the backend dir.

[robsavoye]

I think it does need to be called tests, and be more top level so pytest works. Btw, thank you for adding tests! This is something FMTM is seriously lacking, so every little bit helps.

[spwoodcock]

Also, check the failing tests in the pytest run - they are showing valid errors.
E.g. the file /opt/app/test_data/building_footprint.zip is missing from the PR.

[nrjadkry]

@spwoodcock pytest does not find the tests written outside the app directory. We might need to fix that to write the tests outside of app directory.