Add command to copy current file:line for working with external tools (#14793)

Closes #14787.

I made a quick draft implementation of this feature request:
https://github.com/zed-industries/zed/issues/14787

I know how to use use gdb well, so lacking a built-in debugger is OK.
BUT... Speaking personally, setting breakpoints is 50% of what I want an
IDE to do for me when debugging. Having a feature where I can click,
copy, "b [paste]", is a huge step up from typing the whole thing in
manually. I figure this must be useful for other external tools, or even
just regular-human-communication too.

Open Questions:
* Does this belong in the right click menu? (I put it next to "Copy
Permalink" which is similar.)
* Probably not useful enough to get a default keymap?
* Relative vs absolute path?
* Does this need tests?

Release Notes:

- Added `editor: copy file location` command to copy the current file
location (FILE:LINE) to the clipboard
([#14787](https://github.com/zed-industries/zed/issues/14787)).

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>

crates/editor/src/actions.rs

@@ -199,6 +199,7 @@ gpui::actions!(
         CopyHighlightJson,
         CopyPath,
         CopyPermalinkToLine,
+        CopyFileLocation,
         CopyRelativePath,
         Cut,
         CutToEndOfLine,

crates/editor/src/editor.rs

@@ -10905,6 +10905,17 @@ impl Editor {
         }
     }
 
+    pub fn copy_file_location(&mut self, _: &CopyFileLocation, cx: &mut ViewContext<Self>) {
+        if let Some(buffer) = self.buffer().read(cx).as_singleton() {
+            if let Some(file) = buffer.read(cx).file().and_then(|f| f.as_local()) {
+                if let Some(path) = file.path().to_str() {
+                    let selection = self.selections.newest::<Point>(cx).start.row + 1;
+                    cx.write_to_clipboard(ClipboardItem::new_string(format!("{path}:{selection}")));
+                }
+            }
+        }
+    }
+
     pub fn open_permalink_to_line(&mut self, _: &OpenPermalinkToLine, cx: &mut ViewContext<Self>) {
         let permalink = self.get_permalink_to_line(cx);
 

crates/editor/src/element.rs

@@ -353,6 +353,7 @@ impl EditorElement {
         register_action(view, cx, Editor::copy_highlight_json);
         register_action(view, cx, Editor::copy_permalink_to_line);
         register_action(view, cx, Editor::open_permalink_to_line);
+        register_action(view, cx, Editor::copy_file_location);
         register_action(view, cx, Editor::toggle_git_blame);
         register_action(view, cx, Editor::toggle_git_blame_inline);
         register_action(view, cx, Editor::toggle_hunk_diff);