Add rename subgroup option

[priyanshu16095]

Fixes #11896

This PR adds the functionality to rename a subgroup using the F2 keybinding.
It converts the text into a text field, allowing the user to change the name, providing a better user experience.

Mandatory checks

• I own the copyright of the code submitted and I licence 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 (for UI changes)
• Checked developer's documentation: Is the information available and up to date? If not, I outlined it in this pull request.
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[priyanshu16095]

@priyanshu16095 I hope you have seen the comments on the PR - F2 should just open the groups edit window (which already focuses the gorup name IMHO)

I have implemented this in a different way, like in VS Code.

[Siedlerchr]

On mac pressing Fn + F2 does not do anything right now :(
Fn + F1 correclty opens the help

[priyanshu16095]

Yeah, it currently doesn't work properly.

The issues are:

• Keybinding
• The text field does not appear

But the renaming works fine.
I pushed this code to work on another branch.

[koppor]

I think, code to check for an existing group is missing.

Since this gets very complex, my proposal was to just open the existing groups dialog.

When pressing F2 just the functionality of "Edit group" should be called. I know that the UX is not that good, but this UI issue is not a high priority one. And with F2 working, the user intention is adressed.

[priyanshu16095]

Recording.2025-02-27.mp4

Now, the keybinding works fine.