Revert "file_finder: Remove common segments of long paths in search results (#25049)" (#25163)

This reverts commit 9ef0501853 due to a
panic.

```
{
  "thread": "main",
  "payload": "9 is not a valid char boundary in path \"crates/…/LiveKitBridge/\"",
  "location_data": {
    "file": "crates/file_finder/src/file_finder.rs",
    "line": 646
  }
}
```

Release Notes:

- N/A

crates/assistant_slash_command/src/assistant_slash_command.rs

@@ -88,7 +88,7 @@ pub trait SlashCommand: 'static + Send + Sync {
     fn accepts_arguments(&self) -> bool {
         self.requires_argument()
     }
-
+    #[allow(clippy::too_many_arguments)]
     fn run(
         self: Arc<Self>,
         arguments: &[String],