Fix for issue 3052

[halx4]

This is an atempt to fix the problem with entry editor focus as described in #3052. In detail, when EntryEditor opens up, it is not focused automatically. The desired behavior is to focus the first Textfield on any of the EntryEditor's tabs.

The way the fix is implemented: when EntryEditor is opened, the JFXPanel in which is the TabPane of the EntryEditor is getting the focus, The focus is given implicitly to a focusTraversable node contained in the JFXPanel. The selection of the node seems to be "random" (even though consistent for a given tree of nodes). As far as I've tested it consistently focuses the first Textfield on any tab, which is the desired behavior. I make this pull requested as suggested in #3052 discussion by @Siedlerchr .

I should mention that I ran gradle check which results in "6 tests failed" in my setup but this was also the result when I ran the test before making any change.

• Change in CHANGELOG.md described
• Tests created for changes
• Screenshots added (for bigger UI changes)
• Manually tested changed features in running JabRef
• Check documentation status (Issue created for outdated help page at help.jabref.org?)
• If you changed the localization: Did you run gradle localizationUpdate?

[tobiasdiez]

Thanks for the PR!