[test][assetwidget] Improve algorithm migration test

It ensure that the declaration loaded matches the one
from the migrated algorithm.
4 jobs for 275_fix_algorithm_migration in 26 minutes and 56 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #205486
docker
build_linux_36

00:11:37

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passed #205487
docker
build_linux_37

00:11:21

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passed #205484
macosx
build_macosx_36

00:26:56

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passed #205485
macosx
build_macosx_37

00:26:17

90.0%