repl: Replace REPL panel with sessions view (#14981)

This PR removes the REPL panel and replaces it with a new sessions view
that gets displayed in its own pane.

The sessions view can be opened with the `repl: sessions` command (we
can adjust the name, as needed).

There was a rather in-depth refactoring needed to extricate the various
REPL functionality on the editor from the `RuntimePanel`.

<img width="1136" alt="Screenshot 2024-07-22 at 4 12 12 PM"
src="https://github.com/user-attachments/assets/ac0da351-778e-4200-b08c-39f9e77d78bf">

<img width="1136" alt="Screenshot 2024-07-22 at 4 12 17 PM"
src="https://github.com/user-attachments/assets/6ca53476-6ac4-4f8b-afc8-f7863f7065c7">

Release Notes:

- N/A

crates/repl/src/repl.rs

@@ -7,15 +7,16 @@ use std::{sync::Arc, time::Duration};
 mod jupyter_settings;
 mod kernels;
 mod outputs;
+mod repl_editor;
+mod repl_sessions_ui;
 mod repl_store;
-mod runtime_panel;
 mod session;
 mod stdio;
 
 pub use jupyter_settings::JupyterSettings;
 pub use kernels::{Kernel, KernelSpecification, KernelStatus};
-pub use runtime_panel::{ClearOutputs, Interrupt, Run, Shutdown};
-pub use runtime_panel::{RuntimePanel, SessionSupport};
+pub use repl_editor::*;
+pub use repl_sessions_ui::{ClearOutputs, Interrupt, ReplSessionsPage, Run, Shutdown};
 pub use runtimelib::ExecutionState;
 pub use session::Session;
 
@@ -48,7 +49,7 @@ fn zed_dispatcher(cx: &mut AppContext) -> impl Dispatcher {
 pub fn init(fs: Arc<dyn Fs>, cx: &mut AppContext) {
     set_dispatcher(zed_dispatcher(cx));
     JupyterSettings::register(cx);
-    editor::init_settings(cx);
-    runtime_panel::init(cx);
+    ::editor::init_settings(cx);
+    repl_sessions_ui::init(cx);
     ReplStore::init(fs, cx);
 }