Inconsistent database names across docker compose files

[ppawlowski]

In both docker compose files we create a database required to run FlowFuse container. However, there is a inconsistency in the database naming convention.
In very specific situation this may lead to application container startup failure.
The edge case notices:

• use quick start docker compose to create stack
• stop stack without deleting volumes
• start stack using regular docker compose file
• application container will fail with error database not found error

The goal of this task is to ensure that the same database naming convention is used in both compose files.

[ppawlowski]

Database initialization scripts are executed only once (when the data directory is empty), so renaming the database is not a problem. However, things get tricky when it comes to the core application configuration. Since Compose files follow a declarative approach and offer very limited support for dynamic scripting, I don't see a way to handle this change smoothly without involving customers.
For now, this can be managed manually: inform users about the breaking change and provide an option to customize the database name via the .env file.
If we eventually move to generating Compose files through a script, we can introduce a wrapper to apply the new database name for fresh installations while retaining the old naming convention for existing deployments.

So far we see the problem only once, when customer used quick-start approach first and moved to 'regular' one afterwards and failed due to the database change. Due to this I will put this on hold for now.