feature(tag-db): add tag and study_tag tables to the db (migration)

[mabw-rte]

Context:
Currently, tags do not have a specific table but are directly retrieved from Patches using Python code.

Issue:
This coding paradigm results in filtering that cannot occur at the database level but rather post-query (posing a problem for pagination). It can also potentially slightly slow down API queries.

Solution in following steps:

• Create two tables, Tags and study_tag, to manage the many-to-many relationships between studies and tags. This step requires data migration.
• Update endpoints and services
• Create an update script to populate the newly created tables with pre-existing data.

Note:
This PR deals with the first step.