vim: Fix escape key switching back to default mode instead of normal mode (#31843)

Closes #31728

This PR introduced new setting `"helix_mode"`. Enabling which will
enable the `vim_mode` along with `helix` behavior.

This solves issue where `vim`'s `default_mode` was being used to switch
between mode instead of opening in `default_mode`.

When `helix_mode` is enabled switcing to `Normal mode` will now switch
to `HelixNormal`


Release Notes:

- Fixed - escape key not switching to normal mode when default_mode is
insert
- Added - `helix_mode` setting to enable/disable helix key bindings

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/zed/Cargo.toml

@@ -65,6 +65,7 @@ git_ui.workspace = true
 go_to_line.workspace = true
 gpui = { workspace = true, features = ["wayland", "x11", "font-kit"] }
 gpui_tokio.workspace = true
+
 http_client.workspace = true
 image_viewer.workspace = true
 indoc.workspace = true