refactor(frontend): data validation helpers

[eatyourgreens]

normaliseHeaders is now mostly used for general validation of uploaded data, so this renames it to dataValidation.

[sonarcloud[bot]]

Quality Gate passed for 'pkpdapp'

Issues
0 New issues
0 Accepted issues

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

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 76.22%. Comparing base (b387fb6) to head (018d40c).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## development #496 +/- ## ============================================ Coverage 76.22% 76.22% ============================================ Files 108 108 Lines 5594 5594 ============================================ Hits 4264 4264 Misses 1330 1330 ```

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[sonarcloud[bot]]

Quality Gate failed for 'pkpdapp-team_pkpdapp_frontend'

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarCloud