preview tabs: Allow replacing preview tab when using code navigation (#10730)

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`)

crates/language_tools/src/lsp_log.rs

@@ -97,6 +97,7 @@ pub fn init(cx: &mut AppContext) {
                     Box::new(cx.new_view(|cx| {
                         LspLogView::new(workspace.project().clone(), log_store.clone(), cx)
                     })),
+                    None,
                     cx,
                 );
             }