[Feature Request]: MenuItem mnemonic access keys on frameless windows

### Preflight Checklist

- [X] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/main/CONTRIBUTING.md) for this project.
- [X] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/main/CODE_OF_CONDUCT.md) that this project adheres to.
- [X] I have searched the [issue tracker](https://www.github.com/electron/electron/issues) for a feature request that matches the one I want to file, without success.

### Problem Description

Windows menus provide [mnemonic access keys](https://learn.microsoft.com/en-us/windows/win32/menurc/about-menus#menu-access-keys) to quickly pop open menuitems.

For instance, pressing `Alt+F` will open the File submenu. `Alt+E` for the Edit menu, and so on.

In Electron, these mnemonic access keys work as long as the window has a frame. This gist can be used to test: https://gist.github.com/samuelmaddock/feff0f68418a4f42ee96e3af1868ce56

When `frame: false` is set, the access keys do nothing. Even setting an `accelerator` option will not open the menu item.

### Proposed Solution

Implement key handling to forward these Alt access keys to open the menu.

### Alternatives Considered

Although less convenient, maybe programmatic access to open a menu to a specific submenu.

### Additional Information

_No response_