Set up Rust debugger code runner tasks (#27571)

## Summary 
This PR starts the process of adding debug task locators to Zed's
debugger system. A task locator is a secondary resolution phase that
allows a debug task to run a command before starting a debug session and
then uses the output of the run command to configure itself.

Locators are most applicable when debugging a compiled language but will
be helpful for any language as well.

## Architecture

At a high level, this works by adding a debug task queue to `Workspace`.
Which add's a debug configuration associated with a `TaskId` whenever a
resolved task with a debug config is added to `TaskInventory`'s queue.
Then, when the `SpawnInTerminal` task finishes running, it emits its
task_id and the result of the ran task.

When a ran task exits successfully, `Workspace` tells `Project` to start
a debug session using its stored debug config, then `DapStore` queries
the `LocatorStore` to configure the debug configuration if it has a
valid locator argument.

Release Notes:

- N/A

crates/terminal/src/terminal.rs

@@ -110,6 +110,7 @@ pub enum Event {
     SelectionsChanged,
     NewNavigationTarget(Option<MaybeNavigationTarget>),
     Open(MaybeNavigationTarget),
+    TaskLocatorReady { task_id: TaskId, success: bool },
 }
 
 #[derive(Clone, Debug)]
@@ -1899,6 +1900,11 @@ impl Terminal {
             unsafe { append_text_to_term(&mut self.term.lock(), &lines_to_show) };
         }
 
+        cx.emit(Event::TaskLocatorReady {
+            task_id: task.id.clone(),
+            success: finished_successfully,
+        });
+
         match task.hide {
             HideStrategy::Never => {}
             HideStrategy::Always => {