Add a "test connection" button in the Database Connection screen in Azure Portal

**Is your feature request related to a problem? Please describe.**
Debugging Static Web App's Database Connection feature (also known as Azure Data API Builder) is very very difficult because no information gets exposed about what is going wrong. I'm currently having this problem and it's described in detail at https://github.com/Azure/data-api-builder/issues/1814.

Locally everything works fine, but when deploying to Azure Static Web App it fails.

**Describe the solution you'd like**
Currently the Azure Portal already mentions that the database needs to accept traffic and needs to allow traffic from other Azure Services. Why not add a "Test connection" button which performs a basic request to the Data Api Builder service (from the SWA) so the connection can be verified?

Maybe there could even be a 2nd button/popup that allows you to do a more advanced request that retrieves a specific entity, ensuring the entire chain should work.

If things do not work, more detailed debug information should be shown.

**Describe alternatives you've considered**
Better debug information in the error messages from Azure Data Api Builder, though that probably doesn't belong here. Anyway, the button would be a lot more UX friendly.

Another alternative is not even requiring a button and testing the connection more thoroughly when a database connection is added so it should always work.

**Additional context**
None