Feature Request: Support Shift-F10 to invoke right-click context menu

Apologies if this is a duplicate. I searched and couldn't find an existing issue.

Unfortunately, macOS doesn't natively support invoking the right-click context menu from the keyboard as is possible with the menu keyboard button or SHIFT-F10 on Windows and Linux. The solution associated with the accessibility feature to invoke CTRL-5(number pad) is insufficient because it opens the context menu where the mouse pointer is, not where the text cursor is.

However, third party applications such as Eclipse and IntelliJ on macOS do support this feature with custom application code. Eclipse implemented such functionality in this bugzilla: https://bugs.eclipse.org/bugs/show_bug.cgi?id=219305

This feature request covers adding this functionality to MacVim via the SHIFT-F10 keyboard combination. To be clear, the behaviour is to open the context menu at the keyboard arrow key cursor location, as opposed to the mouse cursor location. For example, this means when moving a keyboard cursor over a misspelled word, the context menu will display with, among other things, suggested spelling corrections for that word, irrespective of where the mouse pointer happens to be.

この issue には、ソースファイル、テスト、エントリーポイントが記載されていません。まず、MacVim における Shift-F10 の処理と、既存のコンテキストメニュー呼び出しを見つけ、次にキーボードカーソルの位置がどのように決定されるかを追跡してください。Shift-F10 がマウスポインターではなくキーボードカーソルの位置でコンテキストメニューを開き、スペルミスのある単語についても同様に動作すれば完了です。