Fix inserting new entry

[LoayGhreeb]

New entries were not correctly bound to the entry editor and main table because they were cloned before being added to the database.

Follow-up to #11724.
Closes https://github.com/JabRef/jabref-issue-melting-pot/issues/656

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.
• 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]

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[koppor]

Check with copy and paste between libraries!

[LoayGhreeb]

Check with copy and paste between libraries!

Tested and working!

[calixtus]

I have no idea what the reasoning was for cloning the entries. @tobiasdiez do you remember?

[LoayGhreeb]

The clone added in #11915

[koppor]

The clone added in #11915

OK, then we merge and check the citation relation tab code later. When looking on it on the mobile phone, chances are high that the result of the merge entries dialog is a new Obect.