open picker (#14524)

Release Notes:

- linux: Added a fallback Open picker for when XDG is not working
- Added a new setting `use_system_path_prompts` (default true) that can
be disabled to use Zed's builtin keyboard-driven prompts.

---------

Co-authored-by: Max <max@zed.dev>

crates/project/src/project.rs

@@ -7559,6 +7559,24 @@ impl Project {
         }
     }
 
+    pub fn completions_for_open_path_query(
+        &self,
+        query: String,
+        cx: &mut ModelContext<Self>,
+    ) -> Task<Result<Vec<PathBuf>>> {
+        let fs = self.fs.clone();
+        cx.background_executor().spawn(async move {
+            let mut results = vec![];
+            let expanded = shellexpand::tilde(&query);
+            let query = Path::new(expanded.as_ref());
+            let mut response = fs.read_dir(query).await?;
+            while let Some(path) = response.next().await {
+                results.push(path?);
+            }
+            Ok(results)
+        })
+    }
+
     fn create_local_worktree(
         &mut self,
         abs_path: impl AsRef<Path>,