Differentiate Menu Popover opened via contextMenu trigger

### Provide a general summary of the feature here

Currently I'm setting a margin on menu's Popover via CSS. The value depends on whether there's OverlayArrow.

When trigger is `contextMenu`, the margin should be 0. However, there's no way to tell from CSS.

### 🤔 Expected Behavior?

A way to differentiate Menu Popover's trigger.

### 😯 Current Behavior

No way to differentiate Menu Popover's trigger.

### 💁 Possible Solution

_No response_

### 🔦 Context

NA

### 💻 Examples

_No response_

### 🧢 Your Company/Team

_No response_

### 🕷 Tracking Issue

_No response_

Start at the Menu Popover entry point and trace how the contextMenu trigger is passed through the menu components and exposed to styling. Compare the contextMenu and other trigger paths; the work is done when CSS can reliably distinguish the contextMenu popover and apply the requested margin behavior.

Written by the indexing model from the issue text.