[x] I have added to CHANGELOG.md relevant changes and any other user facing change
[x] I have added or ran the appropriate tests
What this PR does / why we need it:
The documentation on the database schema for Astarte is a bit outdated and doesn't report correct information.
The PR updates the columns of the database tables presented on the Astarte Database page to match the actual queries run to create the tables.
It also adds some descriptions to better explain the setup process of the database tables, and the typical values that are inserted when initializing Astarte or a new ScyllaDB keyspace.
Special notes for your reviewer:
The PR doesn't currently apply comprehensive changes to the documentation page, such as describing all queries that are run by Astarte services on the database.
What this PR does / why we need it:
The documentation on the database schema for Astarte is a bit outdated and doesn't report correct information.
The PR updates the columns of the database tables presented on the Astarte Database page to match the actual queries run to create the tables.
It also adds some descriptions to better explain the setup process of the database tables, and the typical values that are inserted when initializing Astarte or a new ScyllaDB keyspace.
Special notes for your reviewer:
The PR doesn't currently apply comprehensive changes to the documentation page, such as describing all queries that are run by Astarte services on the database.
Does this PR introduce a user-facing change?