Convex improvement

[pierre-H]

Hi,
The Convex template could be improved the following way :

• Convex needs three URLs. The current template has by default only two URLs : the dashboard and the API. The http router is missing.
• we can use convex with PostgreSQL or MariaDB/Mysql : it would be great to have templates for that config (for the name of the database, check this discussion.
• it would be great to be able to import/export the database, like with MySQL/MariaDB and Postgre, with backups, directly from coolify