Implement "join pane into next" (#16077)

Closes #12409

Release Notes:

- Added "join pane into next" action ([#12409](https://github.com/zed-industries/zed/issues/12409))


https://github.com/zed-industries/zed/assets/727422/00cc8599-e5d6-4fb8-9f0d-9b232d2210ef

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Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/terminal_view/src/terminal_panel.rs

@@ -347,7 +347,7 @@ impl TerminalPanel {
         match event {
             pane::Event::ActivateItem { .. } => self.serialize(cx),
             pane::Event::RemovedItem { .. } => self.serialize(cx),
-            pane::Event::Remove => cx.emit(PanelEvent::Close),
+            pane::Event::Remove { .. } => cx.emit(PanelEvent::Close),
             pane::Event::ZoomIn => cx.emit(PanelEvent::ZoomIn),
             pane::Event::ZoomOut => cx.emit(PanelEvent::ZoomOut),