Fix phase / asset GIS bug

[smcalilly]

Overview

• closes #224
• closes #223

includes:

• gis bug fix (#224)
• districts overwritten fix (#223)
• refactoring of the signals (see notes)
• tests (~half of the diff is a geojson test fixture)
• upgraded django to the latest patch version (see latest security release: https://www.djangoproject.com/weblog/2023/may/03/security-releases/)
• upgrade python (3.8 -> 3.9)

Notes

gis bug fix

The comments in that issue include a lot of background about that bug, but TLDR: the intersects query was causing a segmentation fault on posgres when trying to find the intersection of political districts and a phase's assets. This happened sometimes, but not always. To fix, I'm filtering first with the dwithin function, then doing the intersection. The dwithin function trims down the area where we want to find the intersection. I've added a comment to this PR so you can see the dwithin change, since this diff is bigger with the refactor.

Update: I've upgraded postgis in the docker container so this is fixed on local development. We're migrating to CCFP's servers, so we'll hold off on fixing this on heroku (see this comment: https://github.com/fpdcc/ccfp-asset-dashboard/issues/224#issuecomment-1549877563)

signal refactor

Also includes a refactor of the django signal and GIS processing code. This fixes #223.

I've refactored all of the GIS logic into a class. I also found that a lot of the work was duplicated across signals, so I've consolidated all of the asset-related signals into one single signal so there's not as much redundant work (see this comment in the bug issue about the inefficient, redundant code). This also makes all of the GIS processing logic easier to debug, follow, etc, since it's all in one place rather than split across signals.

Testing Instructions

• visit this project on the review app: https://ccfp-asset-d-patch-sign-5yfa9e.herokuapp.com/projects/2/
  • login with temp credentials: username=admin && password=password
• in the project detail view linked above, scroll down and click "edit assets"
• search for an asset in cook county. bonus points if you find one that is geographically far away from the existing assets of that phase.
• add those assets to the phase. this action should show a success message.
• navigate back to the project overview (click the "overview" button). make sure the scores updated, specifically the political districts, geographic distance score, and social equity score

[smcalilly]

@xmedr woof. thanks for flagging. it's the same memory error that i thought i had fixed. :(

[smcalilly]

@fgregg I upgraded the postgis version for local development and that upgrade GEOS. The dwithin is a workaround but it doesn't address the underlying GEOS issue. Should we merge this code as is or remove dwithin?

[fgregg]

yeah remove dwithin