Make sure that task fixtures loads data from the project

[etj]

Is seems that fixtures are loaded from the main geonode fixtures/ folder and NOT from the project folder

[etj]

https://docs.djangoproject.com/en/5.2/topics/db/fixtures/#how-fixtures-are-discovered

[etj]

1. fixtures/ should be moved within the app for django to be able to find it
2. it seems that files with the same name are all loaded into the db with upsert logic.
   i.e.: in the project we modified a description of a topic category in the initial_data.json, and removed another one
   The final DB contained also the removed topicCategory, and the modified description
   It means that django first loaded the geonode/fixtures/initial_data.json file, and then the projectXXX/fixtures/initial_data.json file