debugger beta: Move path resolution to resolve scenario instead of just in new session modal (#31185)

This move was done so debug configs could use path resolution, and
saving a configuration from the new session modal wouldn't resolve paths
beforehand.

I also added an integration test to make sure path resolution happens
from an arbitrary config. The test was placed under the new session
modal directory because it has to do with starting a session, and that's
what the new session modal typically does, even if it's implicitly used
in the test.

In the future, I plan to add more tests to the new session modal too.

Release Notes:

- debugger beta: Allow configs from debug.json to resolve paths

crates/debugger_ui/src/session/running.rs

@@ -7,7 +7,10 @@ pub mod variable_list;
 
 use std::{any::Any, ops::ControlFlow, path::PathBuf, sync::Arc, time::Duration};
 
-use crate::persistence::{self, DebuggerPaneItem, SerializedLayout};
+use crate::{
+    new_session_modal::resolve_path,
+    persistence::{self, DebuggerPaneItem, SerializedLayout},
+};
 
 use super::DebugPanelItemEvent;
 use anyhow::{Context as _, Result, anyhow};
@@ -543,6 +546,32 @@ impl RunningState {
         }
     }
 
+    pub(crate) fn relativlize_paths(
+        key: Option<&str>,
+        config: &mut serde_json::Value,
+        context: &TaskContext,
+    ) {
+        match config {
+            serde_json::Value::Object(obj) => {
+                obj.iter_mut()
+                    .for_each(|(key, value)| Self::relativlize_paths(Some(key), value, context));
+            }
+            serde_json::Value::Array(array) => {
+                array
+                    .iter_mut()
+                    .for_each(|value| Self::relativlize_paths(None, value, context));
+            }
+            serde_json::Value::String(s) if key == Some("program") || key == Some("cwd") => {
+                resolve_path(s);
+
+                if let Some(substituted) = substitute_variables_in_str(&s, context) {
+                    *s = substituted;
+                }
+            }
+            _ => {}
+        }
+    }
+
     pub(crate) fn new(
         session: Entity<Session>,
         project: Entity<Project>,
@@ -752,6 +781,7 @@ impl RunningState {
                 mut config,
                 tcp_connection,
             } = scenario;
+            Self::relativlize_paths(None, &mut config, &task_context);
             Self::substitute_variables_in_config(&mut config, &task_context);
 
             let request_type = dap_registry