Column Check for Bibtex Parser

[Zurtar]

Closes #12929
Added a column counter and check for Bibtex parsing.

Mandatory checks

• I own the copyright of the code submitted and I license it under the MIT license
• Change in CHANGELOG.md described in a way that is understandable for the average user (if change is visible to the user)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• [/] Screenshots added in PR description (if change is visible to the user)
• Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
• Checked documentation: Is the information available and up to date? If not, I created an issue at https://github.com/JabRef/user-documentation/issues or, even better, I submitted a pull request to the documentation repository.

[jabref-machine]

JUnit tests are failing. You can see which checks are failing by locating the box "Some checks were not successful" on the pull request page. To see the test output, locate "Tests / Unit tests (pull_request)" and click on it.

You can then run these tests in IntelliJ to reproduce the failing tests locally. We offer a quick test running howto in the section Final build system checks in our setup guide.

[koppor]

@Zurtar Please add a test case for the issue addressed.

At first sight, the fix looks good.

Changelog should be "Changed" section as jabrefs behavior changed

[jabref-machine]

Your pull request conflicts with the target branch.

Please merge upstream/main with your code. For a step-by-step guide to resolve merge conflicts, see https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/addressing-merge-conflicts/resolving-a-merge-conflict-using-the-command-line.

[trag-bot]

The logic here does not follow the fail-fast principle. It should return early if the condition is not met, rather than using 'continue'.