Centralize the CopyPath and CopyRelativePath actions to zed_actions (#24836)

I spent an hour with @marcospb19 this morning debugging an issue with
adding `Copy Path` and `Copy Relative Path` actions to the editor
context menu. Turned out that the problem was using
`workspace::CopyPath` in the menu and `editor::CopyPath` in the action
handler.

This is an easy mistake to make, so let's fix it for everyone.

Release Notes:

- N/A

Cargo.lock

@@ -8984,6 +8984,7 @@ dependencies = [
  "util",
  "workspace",
  "worktree",
+ "zed_actions",
 ]
 
 [[package]]
@@ -10179,6 +10180,7 @@ dependencies = [
  "util",
  "workspace",
  "worktree",
+ "zed_actions",
 ]
 
 [[package]]
@@ -16248,6 +16250,7 @@ dependencies = [
  "ui",
  "util",
  "uuid",
+ "zed_actions",
 ]
 
 [[package]]