Add test for parseFieldAndModifiers

[koppor]

There should be test cases for org.jabref.logic.citationkeypattern.BracketedPattern#parseFieldAndModifiers.

Reason: It is not directly clear what this function does - and tests would "document" it.

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Background: Risen by JabRef#13295

[JunWang222]

Hi @koppor , I'm Jun, an MSCS student at NYU. I'd like to take this issue! I'll read through the method and write some parameterized tests to document the behavior. Also applying for GSoC 2026 and really interested in the PostgreSQL backend project — this seems like a good way to get familiar with the codebase first.

[koppor]

@JunWang222 Any issue is useful. We also tagged issues related to seerch with "component: search".