Add abstract param layout formatter test

[leaf-soba]

• add unit test and refactor AbstractParamLayoutFormatter.parseArgument
• reason:

1. origin parseArgument method use too many if-else to make it confusing.
2. I want to refactor it but it don't have any unit test.

• screenshot:

Mandatory checks

• Change in CHANGELOG.md described in a way that is understandable for the average user (if applicable)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• Screenshots added in PR description (for UI changes)
• 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.

[github-actions]

Your code currently does not meet JabRef's code guidelines.
We use OpenRewrite to ensure "modern" Java coding practices.
The issues found can be automatically fixed.
Please execute the gradle task rewriteRun, check the results, commit, and push.

You can check the detailed error output by navigating to your pull request, selecting the tab "Checks", section "Tests" (on the left), subsection "OpenRewrite".

[InAnYan]

Great code! Now it's much easier to understand the algorithm of the parser