Entry editor: move from textfields to more intelligent controls

[tobiasdiez]

Instead of the textfields that we are currently using, I think it would be more user friendly to have more visual controls that support intelligent inline editing.

That's probably something to discuss at the next JabCon....

Example: https://support.papersapp.com/support/solutions/articles/30000024219-how-to-edit-metadata-fields-of-a-document

[calixtus]

refs https://github.com/JabRef/jabref/pull/10910 and https://github.com/JabRef/jabref/pull/10990