Make device state validation more robust

[Pierre-Gilles]

Pull Request check-list

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• If your changes affects code, did your write the tests?
• Are tests passing? (npm test on both front/server)
• Is the linter passing? (npm run eslint on both front/server)
• Did you run prettier? (npm run prettier on both front/server)
• If you are adding a new features/services, did you run integration comparator? (npm run compare-translations on front)
• Did you test this pull request in real life? With real devices? If this development is a big feature or a new service, we recommend that you provide a Docker image to the community for testing before merging.
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• Did you add fake requests data for the demo mode (front/src/config/demo.js) so that the demo website is working without a backend? (if needed) See https://demo.gladysassistant.com.

NOTE: these things are not required to open a PR and can be done afterwards / while the PR is open.

Description of change

Please provide a description of the change here. It's always best with screenshots, so don't hesitate to add some!

[relativeci]

Job #249: Bundle Size — 6.73MB (0%).

dc5a183 vs 58aeb37

Changed metrics (1/10)

Metric	Current	Baseline
Cache Invalidation	0%	60.15%

Changed assets by type (0/7)

No changes

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View Job #249 report on app.relative-ci.com

[codecov]

Codecov Report

Merging #1480 (4f99c05) into master (58aeb37) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1480   +/-   ##
=======================================
  Coverage   96.59%   96.59%           
=======================================
  Files         616      616           
  Lines        8887     8887           
=======================================
  Hits         8584     8584           
  Misses        303      303           

Impacted Files	Coverage Δ
server/models/device_feature.js	100.00% <ø> (ø)
server/models/device_feature_state.js	100.00% <ø> (ø)
server/models/device_feature_state_aggregate.js	100.00% <ø> (ø)

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