Simplify test projects

[0xced]

What does this PR do?

This PR extracts all the common properties across all test projects (except for Testcontainers.Commons) into the Directory.Build.props file.

Why is it important?

This reduces duplication and makes it easier to maintain test projects.

Related issues

None

[netlify]

✅ Deploy Preview for testcontainers-dotnet ready!

Name	Link
🔨 Latest commit	3b3f3cc
🔍 Latest deploy log	https://app.netlify.com/sites/testcontainers-dotnet/deploys/6478e2be0bbe6b0008f8cb37
😎 Deploy Preview	https://deploy-preview-908--testcontainers-dotnet.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.

[HofmeisterAn]

Thank you for submitting your pull request. In general, it is recommended to discuss pull requests beforehand to minimize unnecessary work (Contributing). I am aware of the current configuration (copy and paste), and it is intentionally.

We are considering the implementation of a multi-repo approach, which is why I made an effort to ensure that the module dependencies remain as autonomous as possible. THB, I am uncertain how to continue here. For a single-repo approach the changes make sense /cc @kiview.

[0xced]

I read the contributing guide but felt that this pull request did not fall into the anything big category. It may look big by the number of files involved but it was merely a search and replace on multiple files. 😉

About the multi-repo approach, I'm not sure it would be a benefit for this project. With 16 open issues and 8 open pull requests it still seems manageable. But I'm not a maintainer so of course I'll let this decision up to you.

[HofmeisterAn]

I spoke with the other TC maintainers, and right now, we do not want to increase coupling across modules, etc. We prefer self-contained configurations.

We really appreciate your help, and it is difficult for me to not accept your PR. Your changes are fine from a technical standpoint, and I understand the intention. But we do not want to make any changes in this direction yet.

[0xced]

The amount of code duplication still itches me but I understand your decision.