Fix duplicate text editor entry

[msujew]

What it does

Closes #14237

Fixes the issue by correctly rebinding the EditorPreviewManager, thereby preventing the @postConstruct method to run twice. Also removes an unnecessary @inject of the EditorPreviewManager.

Lastly, prevents duplicate entries from appearing in the OpenWithService.

How to test

Follow the steps from #14237 and ensure that the entry is only shown once.

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[msujew]

cc @sdirix since the Theia AI change broke it ;)

[sdirix]

Thanks for the fix and the additional improvements contained therein. I tested with and without the patch and can confirm that the issue is fixed.

[sdirix]

FYI we intend to get rid of the AIEditorManager soon. It's one of the items listed in #14143