editor: Fix copy file actions not working in remote environments (#43362)

Closes #42500

Release Notes:

- Fixed all three editor actions not working in remote environments
  - `editor: copy file name`
  - `editor: copy file location`
  - `editor: copy file name without extension`

Here's the before/after:




https://github.com/user-attachments/assets/bfb03e99-2e1a-47a2-bd26-280180154fe3

crates/editor/src/editor.rs

@@ -20234,18 +20234,20 @@ impl Editor {
         _: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        if let Some(file) = self.target_file(cx)
-            && let Some(file_stem) = file.path().file_stem()
-        {
+        if let Some(file_stem) = self.active_excerpt(cx).and_then(|(_, buffer, _)| {
+            let file = buffer.read(cx).file()?;
+            file.path().file_stem()
+        }) {
             cx.write_to_clipboard(ClipboardItem::new_string(file_stem.to_string()));
         }
     }
 
     pub fn copy_file_name(&mut self, _: &CopyFileName, _: &mut Window, cx: &mut Context<Self>) {
-        if let Some(file) = self.target_file(cx)
-            && let Some(name) = file.path().file_name()
-        {
-            cx.write_to_clipboard(ClipboardItem::new_string(name.to_string()));
+        if let Some(file_name) = self.active_excerpt(cx).and_then(|(_, buffer, _)| {
+            let file = buffer.read(cx).file()?;
+            Some(file.file_name(cx))
+        }) {
+            cx.write_to_clipboard(ClipboardItem::new_string(file_name.to_string()));
         }
     }
 
@@ -20519,9 +20521,14 @@ impl Editor {
             .start
             .row
             + 1;
-        if let Some(file) = self.target_file(cx) {
-            let path = file.path().display(file.path_style(cx));
-            cx.write_to_clipboard(ClipboardItem::new_string(format!("{path}:{selection}")));
+        if let Some(file_location) = self.active_excerpt(cx).and_then(|(_, buffer, _)| {
+            let project = self.project()?.read(cx);
+            let file = buffer.read(cx).file()?;
+            let path = file.path().display(project.path_style(cx));
+
+            Some(format!("{path}:{selection}"))
+        }) {
+            cx.write_to_clipboard(ClipboardItem::new_string(file_location));
         }
     }