FEATURE: Use custom transformer for flow exceptions

[markusguenther]

The t3n GraphQL package includes a transformer that bypasses Flow Framework exceptions in GraphQL error handling. The error currently lacks the exception code as part of the information. By including this code (often a timestamp), we can render custom error messages in the backend and support localization.

Relates: #240

[markusguenther]

It is not done yet but hopefully the idea is not so wrong.

[markusguenther]

Hopefully localized now all error messages and warnings we have in the codebase.
The acceptance tests run locally.

[Sebobo]

Still have to verify the change locally but thx already!

The German translation still needs some adjustments.

[markusguenther]

Thanks for the feedback, updated the labels!

[Sebobo]

Hmm when I checkout the branch and build the module I now get 2 error messages:

[markusguenther]

Hmm when I checkout the branch and build the module I now get 2 error messages:

I guess that one error is thrown by the application itself and the other comes from the backend as a flash message.

[markusguenther]

In the end with the PR #241 that should not happen anymore.

[markusguenther]

The behavior did not change, just the labels are different now and as I mentioned, with the validation before creating the tag we prevent having two flash messages.

[Sebobo]

Thx! I squashed the commits a bit and removed the bundled files. Also I fixed the duplicate error message