Debugger implementation (#13433)

###  DISCLAIMER

> As of 6th March 2025, debugger is still in development. We plan to
merge it behind a staff-only feature flag for staff use only, followed
by non-public release and then finally a public one (akin to how Git
panel release was handled). This is done to ensure the best experience
when it gets released.

### END OF DISCLAIMER 

**The current state of the debugger implementation:**


https://github.com/user-attachments/assets/c4deff07-80dd-4dc6-ad2e-0c252a478fe9


https://github.com/user-attachments/assets/e1ed2345-b750-4bb6-9c97-50961b76904f

----

All the todo's are in the following channel, so it's easier to work on
this together:
https://zed.dev/channel/zed-debugger-11370

If you are on Linux, you can use the following command to join the
channel:
```cli
zed https://zed.dev/channel/zed-debugger-11370 
```

## Current Features

- Collab
  - Breakpoints
    - Sync when you (re)join a project
    - Sync when you add/remove a breakpoint
  - Sync active debug line
  - Stack frames
    - Click on stack frame
      - View variables that belong to the stack frame
      - Visit the source file
    - Restart stack frame (if adapter supports this)
  - Variables
  - Loaded sources
  - Modules
  - Controls
    - Continue
    - Step back
      - Stepping granularity (configurable)
    - Step into
      - Stepping granularity (configurable)
    - Step over
      - Stepping granularity (configurable)
    - Step out
      - Stepping granularity (configurable)
  - Debug console
- Breakpoints
  - Log breakpoints
  - line breakpoints
  - Persistent between zed sessions (configurable)
  - Multi buffer support
  - Toggle disable/enable all breakpoints
- Stack frames
  - Click on stack frame
    - View variables that belong to the stack frame
    - Visit the source file
    - Show collapsed stack frames
  - Restart stack frame (if adapter supports this)
- Loaded sources
  - View all used loaded sources if supported by adapter.
- Modules
  - View all used modules (if adapter supports this)
- Variables
  - Copy value
  - Copy name
  - Copy memory reference
  - Set value (if adapter supports this)
  - keyboard navigation
- Debug Console
  - See logs
  - View output that was sent from debug adapter
    - Output grouping
  - Evaluate code
    - Updates the variable list
    - Auto completion
- If not supported by adapter, we will show auto-completion for existing
variables
- Debug Terminal
- Run custom commands and change env values right inside your Zed
terminal
- Attach to process (if adapter supports this)
  - Process picker
- Controls
  - Continue
  - Step back
    - Stepping granularity (configurable)
  - Step into
    - Stepping granularity (configurable)
  - Step over
    - Stepping granularity (configurable)
  - Step out
    - Stepping granularity (configurable)
  - Disconnect
  - Restart
  - Stop
- Warning when a debug session exited without hitting any breakpoint
- Debug view to see Adapter/RPC log messages
- Testing
  - Fake debug adapter
    - Fake requests & events

---

Release Notes:

- N/A

---------

Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>
Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Co-authored-by: Anthony <anthony@zed.dev>
Co-authored-by: Piotr Osiewicz <peterosiewicz@gmail.com>
Co-authored-by: Piotr <piotr@zed.dev>

crates/debugger_ui/src/session/failed.rs

@@ -0,0 +1,30 @@
+use gpui::{FocusHandle, Focusable};
+use ui::{
+    h_flex, Color, Context, IntoElement, Label, LabelCommon, ParentElement, Render, Styled, Window,
+};
+
+pub(crate) struct FailedState {
+    focus_handle: FocusHandle,
+}
+impl FailedState {
+    pub(super) fn new(cx: &mut Context<Self>) -> Self {
+        Self {
+            focus_handle: cx.focus_handle(),
+        }
+    }
+}
+
+impl Focusable for FailedState {
+    fn focus_handle(&self, _: &ui::App) -> FocusHandle {
+        self.focus_handle.clone()
+    }
+}
+impl Render for FailedState {
+    fn render(&mut self, _: &mut Window, _: &mut Context<'_, Self>) -> impl IntoElement {
+        h_flex()
+            .size_full()
+            .items_center()
+            .justify_center()
+            .child(Label::new("Failed to spawn debugging session").color(Color::Error))
+    }
+}