Change document modified_at to only update when uploading a new file

[indigane]

Hitas Pull Request

Description

Documents have a user-visible timestamp for creation and modification. The modification timestamp currently updates for all documents relating to an apartment or housing company when the documents form is submitted. This is because the React form and DRF by default work so that they always save the fields even if they haven't changed.

This PR solves the issue by explicitly only updating the modified_at when a file is uploaded instead of automatically on every .save(). This could have also been solved by checking for changes in the frontend or backend but currently we are only interested in when the document file itself was last updated. This could also have been a new timestamp field but I decided against that as too much overengineering.

The migration in this PR is no-op:

$ python manage.py sqlmigrate hitas 0017
BEGIN;
--
-- Alter field modified_at on aparmentdocument
--
-- (no-op)
--
-- Alter field modified_at on housingcompanydocument
--
-- (no-op)
COMMIT;

Pull request checklist

Check the boxes for each DoD item that has been completed:

• Testing
  • Changes have been tested
  • Automatic tests have been added
• Database
  • Database migrations will work in the DEV & TEST environments

Tickets

HT-769

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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