fix(tags): resolve issue with study.additional_data.patch attribute reading

[laurent-laporte-pro]

Pull Request Description

This pull request resolves an issue encountered when reading the study.additional_data.patch attribute in cases where
the study lacks an additional_data instance.
The additional_data attribute is designed to be optional, but an error occurred when attempting to access it without
ensuring its presence.

Problem Origin

The anomaly originated during the implementation phase of managing tags within the database,
instead of retrieving the list of tags from a designated file "patch.json".

Solution

The code now appropriately checks for the existence of the additional_data instance before attempting to access its
attributes.

• Now, the "patch.json" file is read if the additional_data attribute is missing.
• If additional_data is present, the study.additional_data.patch attribute is read as expected.

Testing

Comprehensive testing has been performed to validate the effectiveness of the implemented solution.

Related pull requests

• feat(tags-db): populate tag and study_tag tables using pre-existing patch data in study_additional_data table #1929
• fix(tags-db): correct tag and study_tag migration script #1934
• feat(tags): handle case-insensitive tags and remove orphans #1937