Upgraded packages and introduced Testcontainers for the integration tests.

[mgernand]

• Upgraded all referenced packages (some had vulnerabilities and/or were deprecated).
• Created a separate test project for every supported database provider.
• Introduced Testcontainers to spin up a container with the database to test.
• The new test projects are now multi-targeted to execute the tests for every supported framework version (net6.0, net7.0, net8.0).