This PR adds support for replacing the current preview tab when using
GoToDefinition. Previously a tab, that was navigated away from, was
converted into a permanent tab and the new tab was opened as preview.
Without `enable_preview_from_code_navigation`:
https://github.com/zed-industries/zed/assets/53836821/99840724-d6ff-4738-a9c4-ee71a0001634
With `enable_preview_from_code_navigation`:
https://github.com/zed-industries/zed/assets/53836821/8c60efcb-d597-40bf-b08b-13faf5a289b6
Note: In the future I would like to improve support for the navigation
history, because right now tabs that are not "normal" project items,
e.g. FindAllReferences cannot be reopened
Release Notes:
- Added support for replacing the current preview tab when using code
navigation (`enable_preview_from_code_navigation`)
20625e98ad