Reduce display_map snapshot creation (#39354)

Re-applies https://github.com/zed-industries/zed/pull/30840

This PR re-applies the initial
[PR](https://github.com/zed-industries/zed/pull/30840). As it was closed
because it was hard to land, because of the many conflicts. This PR
re-applies the changes for it.

In several cases we were creating multiple display_map
snapshots within the same root-level function call.
Creating a display_map snapshot is quite slow, and in some
cases we were creating the snapshot multiple times.

Release Notes:

- N/A

crates/vim/src/normal/substitute.rs

@@ -94,7 +94,10 @@ impl Vim {
                     MotionKind::Exclusive
                 };
                 vim.copy_selections_content(editor, kind, window, cx);
-                let selections = editor.selections.all::<Point>(cx).into_iter();
+                let selections = editor
+                    .selections
+                    .all::<Point>(&editor.display_snapshot(cx))
+                    .into_iter();
                 let edits = selections.map(|selection| (selection.start..selection.end, ""));
                 editor.edit(edits, cx);
             });